BACKGROUND

[0001] Vector magnetic field sensing and high signal readout of magnetic fields is challenging. Resolving vector magnetic fields is a difficult problem due to the insensitivity of sensing mechanism to direction. Complex packaging is performed today with magnetic sensors aligned in three axes and calibrated. This is a costly process. Detecting magnetic state-efficient conversion of spin state variable to charge is also challenging. Detecting the state of a magnet is a central step for magnetic memory (e.g., spin transfer torque magnetic random access memory (STT MRAM)) and magnetic logic devices. Conversion of the magnetic state to charge variable is also a critical step for magnetic spin logic and interconnects.

[0002] Existing magnet detection is based on magnetic tunnel junctions (MTJs) and/or spin current interconnects which suffer from several deficiencies. For example, limited conversion efficiency of spin-to-charge variable mediated by tunneling magneto- resistance (TMR). TMR based readout limits the device resistance to a narrow resistance range (e.g., 4 kilo-Ohms to 8 kilo-Ohm range). Spin current based interconnects are limited in interconnect length due to spin degradation with length. These constraints, result in limited read speeds of MRAM as well as limited interconnect options for spin logic. Some key limitations to vector field sensors are: weak direction sensitivity of exiting methods, packaging requirement for three orthogonal magnetic field sensors, and speed and power limitations of inductive field sensing.

BRIEF DESCRIPTION OF THE DRAWINGS

[0003] The embodiments of the disclosure will be understood more fully from the detailed description given below and from the accompanying drawings of various embodiments of the disclosure, which, however, should not be taken to limit the disclosure to the specific embodiments, but are for explanation and understanding only.

[0004] Figs. 1A-B illustrate a three-dimensional (3D) view and corresponding cross- section, respectively, of a magnetic memory hard-disk drive (HDD) using 2-state, quaternary, or six state magnets, according to some embodiments of the disclosure.

[0005] Figs. 2A-B illustrate two embodiments of the magnetic elements in the HDD.

[0006] Fig. 3 illustrates a HDD with a magnetic field sensor, according to some embodiments of the disclosure. l [0007] Fig. 4 illustrates a plot showing magnetic crystalline energy of a four or quaternary state (4-state) magnet and corresponding 4-state magnet used for forming a 4-state read sensor, in accordance with some embodiments of the disclosure.

[0008] Fig. 5 illustrates a plot showing magnetic crystalline energy of a six state (6- state) magnet and corresponding 6-state magnet used for forming a 6-state read sensor, in accordance with some embodiments of the disclosure.

[0009] Fig. 6 illustrates a cross-sectional view of a magnetic field sensor that uses inverse spin orbit coupling, according to some embodiments of the disclosure.

[0010] Fig. 7 A illustrates a three dimensional (3D) view of a 2-axis magnetic field sensor, according to some embodiments of the disclosure.

[0011] Fig. 7B illustrates a top view of a cross-section of the sensor of Fig. 7A, in accordance with some embodiments.

[0012] Fig. 8 illustrates a cross-sectional view an out-of-plane magnetic field sensor, according to some embodiments of the disclosure.

[0013] Fig. 9A illustrates a 3D view of a 3-axis magnetic field sensor, according to some embodiments of the disclosure.

[0014] Fig. 9B illustrates a top view of a cross-section of the sensor of Fig. 9A, according to some embodiments of the disclosure.

[0015] Fig. 10 illustrates a smart device or a computer system or a SoC (System-on-

Chip) with a magnetic memory hard-disk drive (HDD) using 2-state, 4-state or 6-state magnets which can be sensed by the magnetic field sensor, according to some embodiments.

DETAILED DESCRIPTION

[0016] Various embodiments describe a magnetic field sensor which can sense vector magnetic fields using inverse spin orbit effects. In some embodiments, the magnetic field sensor comprises: a ferromagnet; a first layer comprising an inverse spin orbit coupling material, wherein the first layer is adjacent to the ferromagnet; and a second layer comprising a first non-magnetic metal, wherein the second layer is adjacent to the first layer.

[0017] The magnetic field sensor of some embodiments allows simultaneous sensing of magnetic fields. For example, the magnetic field sensor of some embodiments can sense magnetic fields along the x, y, and z axes, simultaneously. The magnetic field sensor of some embodiments allow the sensing of magnetic fields along three perpendicular axes defined by lithography (and not packaging). The magnetic field sensor of some embodiments, allows inertial navigation and dead reckoning where magnetic field information can be auxiliary information. The magnetic field sensor of some embodiments allow hard disk drive (HDD) media with four and/or six axes anisotropy.

[0018] In the following description, numerous details are discussed to provide a more thorough explanation of the embodiments of the present disclosure. It will be apparent, however, to one skilled in the art, that embodiments of the present disclosure may be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form, rather than in detail, in order to avoid obscuring embodiments of the present disclosure.

[0019] Note that in the corresponding drawings of the embodiments, signals are represented with lines. Some lines may be thicker, to indicate more constituent signal paths, and/or have arrows at one or more ends, to indicate primary information flow direction. Such indications are not intended to be limiting. Rather, the lines are used in connection with one or more exemplary embodiments to facilitate easier understanding of a circuit or a logical unit. Any represented signal, as dictated by design needs or preferences, may actually comprise one or more signals that may travel in either direction and may be implemented with any suitable type of signal scheme.

[0020] Throughout the specification, and in the claims, the term "connected" means a direct connection, such as electrical, mechanical, or magnetic connection between the things that are connected, without any intermediary devices. The term "coupled" means a direct or indirect connection, such as a direct electrical, mechanical, or magnetic connection between the things that are connected or an indirect connection, through one or more passive or active intermediary devices. The term "circuit" or "module" may refer to one or more passive and/or active components that are arranged to cooperate with one another to provide a desired function. The term "signal" may refer to at least one current signal, voltage signal, magnetic signal, or data/clock signal. The meaning of "a," "an," and "the" include plural references. The meaning of "in" includes "in" and "on."

[0021] The terms "substantially," "close," "approximately," "near," and "about," generally refer to being within +/- 10% of a target value (unless specifically specified). Unless otherwise specified the use of the ordinal adjectives "first," "second," and "third," etc., to describe a common object, merely indicate that different instances of like objects are being referred to, and are not intended to imply that the objects so described must be in a given sequence, either temporally, spatially, in ranking or in any other manner.

[0022] For the purposes of the present disclosure, phrases "A and/or B" and "A or B" mean (A), (B), or (A and B). For the purposes of the present disclosure, the phrase "A, B, and/or C" means (A), (B), (C), (A and B), (A and C), (B and C), or (A, B and C). The terms "left," "right/' "front,' ^' "hack," "top," "bottom," "over," "under," and the like in the description and in the claims, if any, are used for descriptive purposes and not necessarily for describing permanent relative positions.

[0023] Figs. 1A-B illustrate a three-dimensional (3D) view 100 and corresponding cross-section 120, respectively, of a magnetic memory hard-disk drive (HDD) using bi-axial, quaternary or six state magnets, according to some embodiments of the disclosure. In some embodiments, HDD comprises a substrate 101 (e.g., glass substrate), a heat spreading layer 102, transition metal layer 103, quaternary or six state recording layer 104, and cladding layer 105.

[0024] In some embodiments, after substrate 101 is formed, heat spreading layer 102 is deposited above substrate 101. In some embodiments, layer 102 is formed of Ru and similar materials. In some embodiments, transition metal layer 103 is formed above heat spreading layer 102. In some embodiments, transition metal layer 103 comprises strain producing substrates such as BTO (e.g., B112T1O20 or Bi4T Oi ₂ .), DySCCb, GaAs, and group III-V substrates. In some embodiments, transition metal layer 103 is formed of one of: Mo, Pd, Cr, or CoCrPt. In some embodiments, transition metal layer 103 is formed of Mo (110) face centered cubic (FCC) lattice.

[0025] In some embodiments, magnetic recording layer 104 is grown above transition metal layer 103. The magnetic recording layer 104 is used for reading and writing data by storing data in magnetic elements arranged in an array (e.g., rows and columns of magnetic elements or components).

[0026] In some embodiments, magnetic recording layer 104 comprises bi-axial magnets. For example, magnetic recording layer 104 comprises in-plane or out-of-plane magnets that have two unique possible magnetization directions.

[0027] In some embodiments, magnetic recording layer 104 comprises magnets with

4-states. In some embodiments, the 4-state logic memory element that forms the recording layer 104 has four uniquely defined logic states. In some embodiments, the four states are separated by high energy barrier (e.g., 40 kT or 60 kT) to provide low error rate operation, where 'k' is Boltzmann constant and 'T' is temperature. As such, magnetic recording layer 104 has twice as high storage density per magnetic recording layer area than a magnetic recording layer formed of 2-state magnets (or bi-axial state magnet).

[0028] In some embodiments, magnetic recording layer 104 comprises magnets with

6-states. In some embodiments, 6-State logic memory element that forms the recording layer 104 has six uniquely defined logic states. In some embodiments, the six states magnetic states are separated by a high energy barrier (e.g., 20 kT, 40 kT, or 60 kT) to provide low error rate operation. In some embodiments, the energy barrier is greater than or at least 10 kT.

[0029] In some embodiments, cladding layer 105 or lubricant 105 is deposited over magnetic recording layer 104 so that a sensor to read and write to magnetic elements can slide over magnetic recording layer 104 smoothly. An example of cladding layer 105 or lubricant 105 is a layer of perfiuoropoly ether (PFPE) which is a chain polymer of fluorine, carbon, and oxygen atoms. In some embodiments, cladding layer 105 or lubricant 105 is a layer that includes one of: Z-Type Perfluoro Poly Ether Lubricant Polymers, Z-Dol 4000 or Z-Tetroal, ZDol 7800, or Cyclotriphosphazenes.

[0030] Figs. 2A-B illustrate two embodiments of the magnetic elements in the HDD.

It is pointed out that those elements of Figs. 2A-B having the same reference numbers (or names) as the elements of any other figure can operate or function in any manner similar to that described, but are not limited to such. Fig. 2A illustrates part of the stack of HDD 200 where cladding layer 105 is formed above magnetic layer 104, and where transition metal layer 103 is adjacent to magnetic layer 104 as shown in Figs. 1A-B. Fig. 2B illustrates an embodiment 220 where instead of the cladding layer 105 being in direct contact with magnetic layer 104, another transition metal layer 201 (e.g., comprises Mo) is formed above magnetic layer 104. In some embodiments, the transition metal 103 is to produce a strain induced transition in the transition metal 201. While this embodiment may form a taller HDD, it results in higher magnetic anisotropy Hkthan the embodiment of Fig. 2A. In some embodiments, a super-lattice of layers of Ru and Mo is formed between layer 103 and layer 105.

[0031] Fig. 3 illustrates an apparatus 300 with a HDD with a bi-axial, quatemary, or six state read head, according to some embodiments of the disclosure. It is pointed out that those elements of Figs. 3 having the same reference numbers (or names) as the elements of any other figure can operate or function in any manner similar to that described, but are not limited to such. In some embodiments, bi-axial, quaternary, or six state read head 303 is provided which includes a read sensor 302 having a quatemary or six state magnet. In some embodiments, bi-axial, quaternary, or six state read head 303 is insulated by magnetic shields 301a and 301b. Any suitable material may be used for forming magnetic shields 301a. Figs. 6-9 describe various embodiments of bi-axial, quaternary, or six state read head 303 which can also be used as standalone magnetic field sensors for any application.

[0032] Fig. 4 illustrates plot 400 showing magnetic crystalline energy of a four state or quaternary state (4-state) magnet and corresponding 4-state magnet used for forming a 4- state read sensor, in accordance with some embodiments of the disclosure. It is pointed out that those elements of Figs. 4 having the same reference numbers (or names) as the elements of any other figure can operate or function in any manner similar to that described, but are not limited to such. Here, the x-axis is angle in degrees, and the y-axis is Energy in kT (where 'k' is Boltzmann constant and ' is temperature). Plot 400 illustrates two waveforms— 402 and 403. Waveform 402 illustrates the thermal energy separation or barrier between four magnetic orientations of 4-state magnet 404. In some embodiments, 4-state magnet 404 is formed of a material such that the four magnetic orientations are separated by 40 kT of thermal energy barrier as illustrated by waveform 402. Waveform 403 is similar to waveform 402 except that the thermal energy separation between the four magnetic orientations is 60 kT. In some embodiments, the 4-state magnetic recording media has four uniquely defined memory states. In some embodiments, the 4-state magnetic recording media is accessed by a 4-state magnetic read head with four uniquely measureable tunnel magnetoresistance (TMR) TMR or Giant magnetoresistance (GMR) outputs.

[0033] In some embodiments, the four orientations are defined for the 4-state logic memory element such that orientations '0' and T are separated by 90 degrees, orientations T and '3' are separated by 90 degrees, orientations '3' and '2' are separated by 90 degrees, orientations '0' and '3' are separated by 180 degrees, and orientations T and '2' are separated by 180 degrees. In some embodiments, with reference to a four quadrant 2D (two dimensional) vector space, magnetic orientation facing +x direction (e.g., East) is orientation 'Ο'; magnetic orientation facing +y direction (e.g., North) is orientation T, magnetic orientation facing -x direction (e.g., West) is orientation '3', and magnetic orientation facing -y direction (e.g., South) is orientation '2'.

[0034] In some embodiments, 4-state magnet 404/104 is formed using cubic magnetic crystalline anisotropy magnets. In some embodiments, 4-state magnet 404 is formed by combining shape and exchange coupling to create two equal easy axes for nanomagnets. In some embodiments, 4-state magnet 404 comprises of a material which includes one or more of: Fe, Ni, Co and their alloys, magnetic insulators, or Heusler alloys of the form X?YZ. In some embodiments, the magnetic insulators comprises of a material which includes one or more of: Fe, O, Y, Al, magnetite Fe304, or Y3AI5O12. In some embodiments, the Heusler alloys comprises one or more of: Co, Fe, Si, Mn, Ga, Co ₂ FeSi or MmGa.

[0035] In some embodiments, 4-state magnet 404 is formed with high spin polarization materials. Heusler alloys are an example of high spin polarization materials. Heusler alloys are ferromagnetic metal alloys based on Heusler phase. Heusler phases are intermetallic phases with particular composition and face-centered cubic (FCC) crystal structure. Heusler alloys are ferromagnetic because of double-exchange mechanism between neighboring magnetic ions. The neighboring magnetic ions are usually manganese ions, which sit at the body centers of the cubic structure and carry most of the magnetic moment of the alloy.

[0036] In some embodiments, Heusler alloys such as Co2FeAl and Co2FeGeGa are used for forming 4-state magnet 404/104. Other examples of Heusler alloys include:

CiteMnAl, Cu ₂ MnIn, Cu ₂ MnSn, Ni ₂ MnAl, Ni ₂ MnIn, Ni ₂ MnSn, Ni ₂ MnSb, Ni ₂ MnGa, Co ₂ MnAl, Co ₂ MnSi, Co ₂ MnGa, Co ₂ MnGe, Pd ₂ MnAl, Pd ₂ MnIn, Pd ₂ MnSn, Pd ₂ MnSb, Co ₂ FeSi, Fe ₂ Val, Mn ₂ VGa, Co ₂ FeGe, etc.

[0037] In some embodiments, 4-state magnet 404 is formed with a sufficiently high anisotropy (Hk) and sufficiently low magnetic saturation (M _s ) to increase injection of spin currents. For example, Heusler alloys of high Hk and low M _s are used to form 4-state magnet 404.

[0038] Magnetic saturation M _s is generally the state reached when an increase in applied external magnetic field H cannot increase the magnetization of the material (i.e., total magnetic flux density B substantially levels off). Here, sufficiently low M _s refers to M _s less than 200 kA/m (kilo- Amperes per meter). Anisotropy Hk generally refers to the material property which is directionally dependent. Materials with Hk are materials with material properties that are highly directionally dependent. Here, sufficiently high Hk in context of Heusler alloys is considered to be greater than 2000 Oe (Oersted). For example, a half metal that does not have bandgap in spin up states but does have bandgap in spin down states (e.g., at the energies within the bandgap, the material has 100% spin up electrons). If the Fermi level of the material is in the bandgap, injected electrons will be close to 100% spin polarized. In this context, "spin up" generally refers to the positive direction of

magnetization, and "spin down" generally refers to the negative direction of magnetization. Variations of the magnetization direction (e.g. due to thermal fluctuations) result in mixing of spin polarizations. [0039] Fig. 5 illustrates plots showing magnetic crystalline energy of a six state (6- state) magnet and corresponding 6-state magnet used for forming a 6-state read sensor, in accordance with some embodiments of the disclosure. It is pointed out that those elements of Figs. 5 having the same reference numbers (or names) as the elements of any other figure can operate or function in any manner similar to that described, but are not limited to such.

[0040] In some embodiments, the 6-state magnetic recording media has six uniquely defined memory states. In some embodiments, the 6-state magnetic recording media is accessed by a 6-state magnetic read head with three to six uniquely TMR or GMR outputs.

[0041] For plot 501a, the x-axis is in-plane angle in degrees, and the y-axis is Energy in kT (where 'k' is Boltzmann constant and ' is temperature). Plot 501a illustrates two waveforms— 502 and 503. Waveforms 502 and 503 illustrate the thermal energy separation or barrier between four in-plane magnetic orientations of the 6-State magnet 507, where waveform 502 has a barrier separation of 40 kT and waveform 503 has a barrier separation of 60 kT. A side-view of 6-State magnet 507 is illustrated as a stack of layers 509/104, in accordance with some embodiments. The stack of layers 509/104 are also referred to as side- view 509/104.

[0042] The other two magnetic orientations of the 6-State magnet 507 are out-of- plane as shown by plot 501b. For plot 501b, the x-axis is out-of-plane angle in degrees, and the y-axis is Energy in kT. Plot 501b illustrates three waveforms— 504, 505, and 506.

Waveforms 504, 505, and 506 illustrates the thermal energy separation or barrier between two out-of-plane magnetic orientations of the 6-state magnet 507, where waveform 504 has a barrier separation of 20 kT, waveform 505 has a barrier separation of 40 kT, and waveform 506 has a barrier separation of 60 kT. While the embodiments described here assume a barrier separation of 40 kT, materials and shape anisotropy for 6-State magnet 507 can be selected to have other barrier separations which are large enough to provide zero error rate between states. For example, the energy barrier can be greater than or at least 10 kT.

[0043] In some embodiments, the six orientations are defined for the 6-State logic memory element such that orientations '0' and T are separated by 90 degrees, orientations T and '3' are separated by 90 degrees, orientations '3' and '2' are separated by 90 degrees, orientations '0' and '3' are separated by 180 degrees, orientations T and '2' are separated by 180 degrees, orientations '0' and '4', '4' and Ί ', '4' and '3', and '4' and '2' are separated by 90 degrees each, orientations '5' and 'Ο', '5' and '2', '5' and '3', and '5' and T, are separated by 90 degrees each, and orientations '5' and '4' are separated by 180 degrees. [0044] In some embodiments, with reference to an eight quadrant three dimensional

(3D) vector space, magnetic orientation facing +x direction (e.g., East) is orientation 'Ο'; magnetic orientation facing +y direction (e.g., North) is orientation T, magnetic orientation facing -x direction (e.g., West) is orientation '3', magnetic orientation facing -y direction (e.g., South) is orientation '2', magnetic orientation facing -z direction is orientation '4', and magnetic orientation facing +z direction is orientation '5. '

[0045] In some embodiments, 6-State magnet 507 is formed using cubic magnetic crystalline anisotropy magnets. In some embodiments, 6-State magnet 507 is formed using shape, crystalline and strain assisted magnetization. One such example is illustrated as a side view 509 of top view of 6-State magnet 507. In the side view 509, 6-State magnet is formed by combining a magnetostrictive (MS) ferromagnet (FM) 507a with a piezo-electric (PZe) layer 508. MS FM 507a is formed of ferromagnetic materials that causes the materials to change their shape or dimensions during the process of magnetization.

[0046] PZe layer 508 causes piezo-electric effect in magnetostrictive ferromagnet

(FM) 507a when a voltage is applied to PZe layer 508. The applied voltage across PZe layer 508 causes change in the magnetic field in MS FM 507a and so it stresses magnetostrictive FM 507a. The stress in turn causes magnetostrictive FM 507a to have six magnetic states. In some embodiments, magnetostrictive FM 507a is formed of any one of the materials:

Terfenol-D (an alloy of the formula Tb _x Dyi- _x Fe2 (x ~ 0.3)), galfenol (an alloy of iron and gallium), amorphous alloy Fe8iSi3.5B13.5C2, or Ni.

[0047] In some embodiments, PZe layer 508 comprises any one of the materials:

Barium titanate (BaTi03), Lead zirconate titanate (PZT), Potassium niobate (KNb03), Sodium tungstate (Na2W03), Ba2NaNb505, Pb2K b50i5, Zinc oxide (ZnO)-Wurtzite structure, Sodium potassium niobate ((K,Na)Nb03) (or NKN), Bismuth ferrite (BiFe03), Sodium niobate NaNb03, Bismuth titanate Βΐ4Τΐ3θΐ2, Sodium bismuth titanate Nao.5Bio.5Ti03, any bulk or nanostructured semiconductor crystal having non central symmetry, such as the Group III-V and II-VI materials, Polyvinylidene fluoride (PVDF), diphenylalanine peptide nanotubes (PNTs), etc.

[0048] In some embodiments, 6-State magnet 507 is formed using shape, exchange coupling, and strain assisted magnetization. In some embodiments, 6-State magnet 507 is formed using in-plane bi-axial anisotropy and strain assisted magnetization. In some embodiments, 6-State magnet 507 is formed using tri-axial anisotropy magnet.

[0049] In some embodiments, 6-State magnet 507 comprises a material which includes one 0 of: Fe, Ni, Co and their alloys, magnetic insulators, and Heusler alloys of the form X?.YZ. In some embodiments, the magnetic insulators are formed of a material selected from a group consisting of: magnetite Fe ₃ 0 ₄ and Y3AI5O12. In some embodiments, the Heusler alloys is one of: Co ₂ FeSi and MmGa.

[0050] In some embodiments, 6-State magnet 507 is formed with high spin polarization materials. Heusler alloys are an example of high spin polarization materials. In some embodiments, 6-State magnet 507 is formed with a sufficiently high Hk and sufficiently low Ms to increase injection of spin currents. For example, Heusler alloys of high Hk and low Ms are used to form 6-State magnet 507. In some embodiments, Heusler alloys such as Co2FeAl and Co2FeGeGa are used for forming 6-state magnet 507. Other examples of Heusler alloys include: Cu ₂ MnAl, Cu ₂ MnIn, Cu ₂ MnSn, Ni ₂ MnAl, Ni ₂ MnIn, Ni ₂ MnSn, Ni ₂ MnSb, Ni ₂ MnGa, Co ₂ MnAl, Co ₂ MnSi, Co ₂ MnGa, Co ₂ MnGe, Pd ₂ MnAl, Pd ₂ MnIn, Pd ₂ MnSn, Pd ₂ MnSb, Co ₂ FeSi, Fe ₂ Val, Mn ₂ VGa, Co ₂ FeGe, etc.

[0051] Fig. 6 illustrates a cross-sectional view 600 of a magnetic field sensor that uses inverse spin orbit coupling, according to some embodiments of the disclosure. It is pointed out that those elements of Figs. 6 having the same reference numbers (or names) as the elements of any other figure can operate or function in any manner similar to that described, but are not limited to such. Here top view 620 is shown for the region along dotted line AA of cross-sectional view 600. The magnetic sensor of Fig. 6 can be used as a standalone magnetic field sensor or detector, and can also be used as a read head for HDD as described with reference to Fig. 3.

[0052] Referring back to Fig. 6, in some embodiments, the magnetic field sensor comprises: non-magnetic metal interconnect or layer 601, ferromagnet (FM) 603, templating layers 604a/b, oxide region 605, non-magnetic metal or interconnect 606, via 607, and a layer of inverse spin orbit coupling material 608. In some embodiments, non-magnetic metal interconnect or layer 601 provides a ground supply to the magnetic field sensor. In some embodiments, FM 603 is a free magnet which is one of: a bi-axial magnet, 4-state magnet as described with reference to Fig. 4, or 6-state magnet as described with reference to Fig. 5. Referring back to Fig. 6, in some embodiments, a bi-axial magnet 603 has in-plane magnetization (e.g., along the plane of the magnetic field sensor). For example, bi-axial magnet 603 has magnetization along the -x or +x directions or along the -y or +y directions.

[0053] In some embodiments, layer of inverse spin orbit coupling (ISOC) material

608 is a single layer which comprises a material which includes one or more of: β-Ta, β-W, W, Pt, Cu doped with Iridium, Cu doped with Bismuth, or Cu doped an element of 3d, 4d, 5d, 4f, or 5f of periodic table groups. In some embodiments, layer 608 is a stack of layers. In some embodiments, the spin polarization is determined by the magnetization of FM 603. In some embodiments, the stack for layer 608 comprises i) an interface layer with a high density 2D (two dimensional) electron gas and with high SOC formed between materials such as Ag or Bi, or ii) a bulk material layer with high Spin Hall Effect (SHE) coefficient such as Ta, W, or Pt.

[0054] In some embodiments, a spacer (or template layer) 604a is formed between

FM 603 and the stack for SOC layer 608. In some embodiments, another template layer 604b is formed under FM 603 to further assist with templating of FM 603. In some embodiments, spacers 604a/b are a templating metal layer which provide a template for forming FM 603. In some embodiments, the metal of the spacers 604a/b, which are directly coupled to FM 603, is a noble metal (e.g., Ag, Cu, or Au) doped with other elements from Group 4d and/or 5d of the Periodic Table. In some embodiments, FM 603 is sufficiently lattice matched to Ag (e.g., a material which is engineered to have a lattice constant close (e.g., within 3%) to that of Ag).

[0055] Here, sufficiently matched atomistic crystalline layers refer to matching of the lattice constant 'a' within a threshold level above which atoms exhibit dislocation which is harmful to the device (for instance, the number and character of dislocations lead to a significant (e.g., greater than 10%) probability of spin flip while an electron traverses the interface layer). For example, the threshold level is within 5% (i.e., threshold levels in the range of 0% to 5% of the relative difference of the lattice constants). As the matching improves (i.e., matching gets closer to perfect matching), spin injection efficiency from spin transfer from FM 603 to ISOC stacked layer 608 increases. Poor matching (e.g., matching worse than 5%) implies dislocation of atoms that is harmful for the device.

[0056] Table 1 summarizes transduction mechanisms for converting magnetization

(i.e. spin state) to charge current and charge current to magnetization for bulk materials and interfaces.

Table 1: Transduction mechanisms for Spin to Charge and Charge to Spin Conversion

[0057] In some embodiments, the spin-orbit mechanism responsible for spin-to- charge conversion is described by the inverse Rashba-Edelstein effect in 2D electron gases. The Hamiltonian (energy) of spin-orbit coupling electrons in a 2D electron gas is:

H _R = a _R (kxz). σ where a _R is the Rashba-Edelstein coefficient, 'k' is the operator of momentum of electrons, z is a unit vector perpendicular to the 2D electron gas, and σ is the operator of spin of electrons.

[0058] The spin polarized electrons with direction of polarization in-plane (e.g., in the xy -plane) experience an effective magnetic field dependent on the spin direction:

a _R .

B (k)= — (fcxz)

½

where i _B is the Bohr magneton

[0059] This results in the generation of a charge current I _c in interconnect 606 proportional to the spin current (or J _s ). The spin-orbit interaction by Ag and Bi interface layers, which are part of layer 608, (e.g., the Inverse Rashba-Edelstein Effect (IREE)) produces a charge current L (e.g., Id) in the horizontal direction given as:

. _ ^ _IREE I _S

W _m

where w _m is width of the FM magnet 603, and _IREE is the IREE constant (with units of length) proportional to a _R .

[0060] Alternatively, the Inverse Spin Hall Effect in Ta, W, or Pt layer of stack forming layer 608 produces the horizontal charge current I _c given as:

2w _m

[0061] Both IREE and ISHE effects produce spin-to-charge current conversion around 0.1 with existing materials at 10 nm (nanometers) magnet width. For scaled nanomagnets (e.g., 5 nm wide magnets) and exploratory SHE materials such as Bi2Se3, the spin-to-charge conversion efficiency can be between 1 and 2.5. The net conversion of the drive charge current Idnve to magnetization dependent charge current is given as:

j _± REEP _for IREE and l _c = ± ^e ™* ^t ™* ^PI * for ISHE

w _m 2w _m

where 'P' is the dimensionless spin polarization. For this estimate, the drive current Idnve and the charge current I _c = I _d = 100 μΑ is set. As such, when estimating the resistance of the ISHE interface to be equal to R = 100 Ω, then the induced voltage is equal to V _ISHE =

10 mV.

[0062] The charge current I _c , carried by interconnect 606 is then sensed by a current sensor (not shown). As magnetic field is received by FM 603, FM 603 develops a magnetization 609 (here, indicating a random direction to illustrate detecting of magnetic flux in any direction) and current I _c is produced on interconnect 606 corresponding to the direction of magnetization 609. In some embodiments, the magnitude of the sensed current indicates the strength of the magnetic field sensed by the magnetic field sensor. In this example, the current detected on interconnect 606 is I _c i=A(m,y), where 'A' is the amplitude of the current flowing along the y-direction and produced by a magnetic component 'm' of the detected magnetic field.

[0063] In some embodiments, materials for FM 603 have saturated magnetization M _s and effective anisotropy field Hk. Saturated magnetization M _s is generally the state reached when an increase in applied external magnetic field H cannot increase the magnetization of the material. Anisotropy Hk generally refers material properties that are highly directionally dependent.

[0064] In some embodiments, materials for layer 603 are non-ferromagnetic elements with strong paramagnetism which have high number of unpaired spins but are not room temperature ferromagnets.

[0065] In some embodiments, FM 603 comprises a material which includes one or more of: Platinum(Pt), Palladium (Pd), Tungsten (W), Cerium (Ce), Aluminum (Al), Lithium (Li), Magnesium (Mg), Sodium (Na), Cr ₂ Cb (chromium oxide), CoO (cobalt oxide), Dysprosium (Dy), Dy20 (dysprosium oxide), Erbium (Er), EnCb (Erbium oxide), Europium (Eu), EU2O3 (Europium oxide), Gadolinium (Gd), Gadolinium oxide (Gd203), FeO and Fe203 (Iron oxide), Neodymium (Nd), Nd2C (Neodymium oxide), KO2 (potassium superoxide), praseodymium (Pr), Samarium (Sm), SrmC (samarium oxide), Terbium (Tb), Tb2C

(Terbium oxide), Thulium (Tm), T1T12O3 (Thulium oxide), or V2O3 (Vanadium oxide). In some embodiments, when layer 603 is formed of non-ferromagnetic elements such as paramagnets, those paramagnets may comprise dopants which include one or more of: Ce, Cr, Mn, Nb, Mo, Tc, Re, Nd, Gd, Tb, Dy, Ho, Er, Tm, or Yb.

[0066] In some embodiments, the stack of layers for layer 608 comprises: a first layer comprising Ag, wherein the first layer is adjacent to FM 603 (or to FM 603 via template layer 608); and a second layer comprising Bi or W, wherein second layer is adjacent to the first layer and to conductor 606. In some embodiments, a third layer (having material which is one or more of Ta, W, or Pt) is sandwiched between the first layer and the second layer. In some embodiments, the stack of layers for layer 608 comprises a material which includes one or more of: β-Ta, β-W, W, Pt, Cu doped with Iridium, Cu doped with Bismuth, and Cu doped an element of 3d, 4d, 5d, 4f, or 5f of periodic table groups.

[0067] In some embodiments, via 607 is provided to couple layer 608 to nonmagnetic metal 601. In various embodiments, non-magnetic metal 601 is coupled to ground. In some embodiments, via 607 is formed of the same material as non-magnetic conductor 601 and 606. For example, via 607 comprises a material which includes one or more of: Cu, Al, Ag, Au, etc. In some embodiments, the material(s) used for forming metal layers 601 and 606 and via 607 is/are the same. For example, Copper (Cu) can be used for forming metal layers 601 and 606, and via 607. In other embodiments, material (s) used for forming metal layers 601 and 606, and via 607 are different. For example, metal layers 601 may be formed of Cu while via 607 may be formed of Tungsten (W). Any suitable metal or combination of metals can be used for forming metal layers 601 and 606, and via 606.

[0068] In some embodiments, another metal layer (not shown) is placed adjacent to layer 604b, where this other metal layer is coupled to a power supply (e.g., +Vdd). This allows spin and charge current to flow from FM 603 towards conductor 601, in accordance with some embodiments.

[0069] Fig. 7A illustrates a three dimensional (3D) view 700 of a 2-axis magnetic field sensor, according to some embodiments of the disclosure. It is pointed out that those elements of Fig. 7A having the same reference numbers (or names) as the elements of any other figure can operate or function in any manner similar to that described, but are not limited to such. So as not to obscure the various embodiments, difference between Fig. 7A and Fig. 6 are described. Compared to magnetic field sensor of Fig. 6, magnetic field sensor of Fig. 7A can provide current information associated with two magnetization direction components. For example, both 'x' and 'y' current directions associated with 'x' and 'y' magnetic components of the magnetic field can be detected and sensed by the sensor of Fig. 7A.

[0070] To detect both the 'x' and 'y' current directions, another non-magnetic interconnect is provided which extends parallel to interconnect 606 (which is now labeled as 606a). The other non-magnetic interconnect here is 606c which is parallel to interconnect 606a. Non-magnetic interconnect 606c is coupled to layer 608 via interconnect 606b which extends orthogonal to interconnect 606c, in accordance with some embodiments.

[0071] Fig. 7B illustrates a top view 720 of a cross-section of the sensor of Fig. 7A, in accordance with some embodiments. It is pointed out that those elements of Fig. 7B having the same reference numbers (or names) as the elements of any other figure can operate or function in any manner similar to that described, but are not limited to such. In this case, the spin current direction in layer 608 causes either or both charge currents la and Id to be generated on interconnects 606a and 606c, respectively. Ia indicates current associated with the +/- 'y' direction of the magnetic field while current Id indicates current associated with the +/- 'x' direction of the magnetic field detected by FM 603. The direction of spin current depends on the direction of magnetization of FM 609, which in turn depends on the direction of magnetic field near FM 609.

[0072] Fig. 8 illustrates a cross-sectional view 800 an out-of-plane magnetic field sensor, according to some embodiments of the disclosure. It is pointed out that those elements of Fig. 8 having the same reference numbers (or names) as the elements of any other figure can operate or function in any manner similar to that described, but are not limited to such. So as not to obscure the embodiments, differences between the sensor of Fig. 6 and Fig. 8 are discussed.

[0073] To detect magnetizations in the +/- z-directions, in some embodiments, FM

603 or layer 603 is replaced with FM 803 or layer 803. Here, magnet 803 has perpendicular magnetic anisotropy (PMA) with out-of-plane magnetization relative to the magnetic field sensor plane. For example, magnet 803 is a free magnet that has magnetization along the -z or +z directions. In some embodiments, spin orbit coupling layer 608 (which provides inverse spin Hall effect) is replaced with layer(s) 808 having material(s) that exhibit inverse Rashba Bychkov effect. Top view 820 illustrates the corresponding top view of cross-section AA of Fig. 8. In some embodiments, channel 606 is able to provide current component in the +/- z-direction associated with spin currents generated from +/- z direction magnetization of FM 803.

[0074] In some embodiments, layer 808 comprises a stack of layers which is to provide an inverse Rashba-Bychkov effect as opposed to Rashba-Edelstein effect. In some embodiments, the stack of layers of layer 808 provides spin-to-charge conversion where a spin current J _s or is injected from FM 803 and charge current I _c is generated by the stack of layers. This charge current I _c is provided to conductor 606 (e.g., charge interconnect). In contrast to spin current, charge current does not attenuate in conductor 606. The direction of the charge current I _c depends on the direction of magnetization of FM 803.

[0075] The FM 803 injects a spin polarized current into the high spin-orbit coupling

(SOC) material stack of layer 608. The spin polarization is determined by the magnetization of FM 803. In some embodiments, the injection stack comprises a material or a

heterostructure which provides Rashba-Bychkov effect. In some embodiments, layer 608 may include the 2D materials which include one or more of: Mo, S, W, Se, Graphene, M0S2, \VSe2, WS2, and MoSe2. In some embodiments, the 2D materials include an absorbent which includes one or more of: Cu, Ag, Pt, Bi, Fr, or H absorbents. [0076] In some embodiments, the spin-orbit mechanism responsible for spin-to- charge current conversion is described by the Rashba-Bychkov effect. Positive currents along the +y axis produce a spin injection current with transport direction along the +z direction and spins pointing to the +z direction.

Jz,sz zzyJy

The spin-orbit interaction by Ag and Bi interface layers (e.g., the Inverse Rashba-Bychkov Effect (IRBE)) produces a charge current I _c in the horizontal direction given as:

. _ ^ _IRBE I _S

W _m

where w _m is width of the FM 803, and _IRYE is the IRYE constant (with units of length) proportional to a _R .

[0077] IRBE effect produces spin-to-charge current conversion around 0.1 with existing materials at 10 nm (nanometers) magnet width. The net conversion of the drive charge current Idrtve to magnetization dependent charge current is given as:

j _ _|_ }RBE ^PI d

c — W _m

where 'P' is the dimensionless spin polarization. For this estimate, the drive current Idrtve (Id) and the P signal charge current I _c = I _d = 100 μΑ is set. Estimating the resistance of the ISHE interface to be equal to R = 100 Ω, then the induced voltage is equal to V _ISHE = 10 mV . The charge current Ic3 is carried by interconnect 606 and can be detected by a current or voltage sensor, in accordance with some embodiments.

[0078] In some embodiments, layer 808 comprises materials ROCI12, where 'R' includes one or more of: La, Ce, Pr, Nd, Sr, Sc, Ga, Al, or In, and where "Ch" is a chalcogenide which comprises one or more of: S, Se, or Te. In some embodiments, layer 808 comprises layers are layers that form hetero-structure with Cu, Ag, Al, and Au. In some embodiments, layer 808 is a stack of layers which comprises a material which includes one or more of: β-Ta, β-W, W, Pt, Cu doped with Iridium, Cu doped with Bismuth, or Cu doped an element of 3d, 4d, 5d, 4f, or 5f of periodic table groups.

[0079] In some embodiments, material(s) for FM 803 have saturated magnetization

Ms and effecting anisotropy field Hk. Saturated magnetization M _s is generally the state reached when an increase in applied external magnetic field H cannot increase the magnetization of the material (i.e., total magnetic flux density B substantially levels off). Anisotropy Hk generally refers to the material property which is directionally dependent. Materials with Hk are materials with material properties that are highly directionally dependent. In some embodiments, a top contact is attached to magnet 803.

[0080] In some embodiments, magnet 803 is a paramagnet as opposed to

ferromagnet. Paramagnets are non-ferromagnetic elements with strong paramagnetism materials which have high number of unpaired spins but are not room temperature ferromagnets.

[0081] In some embodiments, when magnet 803 is a paramagnet 803, it may comprise a material which includes one or more of: Platinum (Pt), Palladium (Pd), Tungsten (W), Cerium (Ce), Aluminum (Al), Lithium (Li), Magnesium (Mg), Sodium (Na), Cr ₂ Cb (chromium oxide), CoO (cobalt oxide), Dysprosium (Dy), Dy20 (dysprosium oxide), Erbium (Er), ErcC (Erbium oxide), Europium (Eu), EU2O3 (Europium oxide), Gadolinium (Gd), Gadolinium oxide (Gd2Cb), FeO and Fe2Cb (Iron oxide), Neodymium (Nd), Nd2Cb

(Neodymium oxide), KO2 (potassium superoxide), praseodymium (Pr), Samarium (Sm), SrmC (samarium oxide), Terbium (Tb), Tb2C (Terbium oxide), Thulium (Tm), TrmCb (Thulium oxide), or V2O3 (Vanadium oxide).

[0082] In some embodiments, when magnet 803 is a paramagnet 803, it may comprise dopants which include one or more of: Ce, Cr, Mn, Nb, Mo, Tc, Re, Nd, Gd, Tb, Dy, Ho, Er, Tm, or Yb. The relaxation time of a paramagnet is enhanced (e.g., made shorter) by doping with materials with stronger dissipation elements to promote Spin-lattice relaxation time (Ti) and Spin-spin relaxation time (T2). Here, the term "Spin-lattice relaxation time (Ti)" generally refers to the mechanism by which the component of the magnetization vector along the direction of the static magnetic field reaches thermodynamic equilibrium with its surroundings. Here, the term "Spin-spin relaxation time (T ₂ )" generally refers to a spin-spin relaxation is the mechanism by which, the transverse component of the magnetization vector, exponentially decays towards its equilibrium value.

[0083] In some embodiments, magnet 803 is a free ferromagnet that is made from

CFGG (i.e., Cobalt (Co), Iron (Fe), Germanium (Ge), or Gallium (Ga) or a combination of them). In some embodiments, FM 803 is a free ferromagnet is a free magnet that is formed from Heusler alloy(s). Heusler alloy is ferromagnetic metal alloy based on a Heusler phase. Heusler phase is intermetallic with certain composition and face-centered cubic (FCC) crystal structure. The ferromagnetic property of the Heusler alloy is a result of a double-exchange mechanism between neighboring magnetic ions.

[0084] In some embodiments, FM 803 has a lattice matched to Ag (e.g., the Heusler alloy is engineered to have a lattice constant close (e.g., within 3%) to that of Ag or to a rotated lattice). In some embodiments, the direction of the spin polarization is determined by the magnetization direction of FM 803.

[0085] In some embodiments, FM 803 comprises a Heusler alloy, Co, Fe, Ni, Gd, B,

Ge, Ga, or a combination of them. In some embodiments, Heusler alloys that form FM 803 include one or more of: Cu, Mn, Al, In, Sn, Ni, Sb, Ga, Ge, Co, Pd, Fe, V, Ru, Cu ₂ MnAl, Cu ₂ MnIn, Cu ₂ MnSn, Ni ₂ MnAl, Ni ₂ MnIn, Ni ₂ MnSn, Ni ₂ MnSb, Ni ₂ MnGa Co ₂ MnAl,

Co ₂ MnSi, Co ₂ MnGa, CoJVInGe, Pd ₂ MnAl, Pd ₂ MnIn, PdJVInSn, PdJVInSb, Co ₂ FeSi, Co ₂ FeAl, Fe ₂ VAl, Mn ₂ VGa, Co ₂ FeGe, MnGa, or MnGaRu.

[0086] In some embodiments, the thickness t _c of FM 803 may determine its magnetization direction. For example, when the thickness of a ferromagnetic layer is above a certain threshold (depending on the material of the magnet, e.g., approximately 1.5 nm for CoFe), then the ferromagnetic layer exhibits magnetization direction which is in-plane.

Likewise, when the thickness of the ferromagnetic layer is below a certain threshold

(depending on the material of the magnet), then the ferromagnetic layer exhibits

magnetization direction which is perpendicular to the plane of the magnetic layer. Other factors may also determine the direction of magnetization. Here, magnet 803 has out-of- plane magnetization (e.g., pointing in the +/- z-direction).

[0087] For example, factors such as surface anisotropy (depending on the adjacent layers or a multi-layer composition of the ferromagnetic layer) and/or crystalline anisotropy (depending on stress and the crystal lattice structure modification such as FCC (face centered cubic) lattice, BCC (body centered cubic) lattice, or Llo-type of crystals, where Llo is a type of crystal class which exhibits perpendicular magnetizations), can also determine the direction of magnetization.

[0088] In some embodiments, magnet 803 is magnetized perpendicular to the plane of the magnetic sensor. In some embodiments, FM 803 with PMA is formed with multiple layers in a stack. The multiple thin layers can be layers of Cobalt and Platinum (i.e., Co/Pt), for example. Other examples of the multiple thin layers include: Co and Pd; Co and Ni; MgO, CoFeB, Ta, CoFeB, and MgO; MgO, CoFeB, W, CoFeB, and MgO; MgO, CoFeB, V, CoFeB, and MgO; MgO, CoFeB, Mo, CoFeB, MgO; Mn _x Ga _y ; Materials with Llo crystal symmetry; or materials with tetragonal crystal structure. In some embodiments, the perpendicular magnetic layer is formed of a single layer of one or more materials. In some embodiments, the single layer is formed of MnGa. In some embodiments, the perpendicular magnetic layer includes one of: a Heusler alloy, Co, Fe, Ni, Gd, B, Ge, Ga, permalloy, YIG (Yttrium iron garnet), or a combination of them. [0089] Fig. 9A illustrates a 3D view 900 of a 3-axis magnetic field sensor, according to some embodiments of the disclosure. It is pointed out that those elements of Fig. 9A having the same reference numbers (or names) as the elements of any other figure can operate or function in any manner similar to that described, but are not limited to such. In some embodiments, 3-axis magnetic field sensor can be formed by merging the distinct features of magnetic field sensors of Fig. 6, Fig. 7, and Fig. 8. In some embodiments, magnet 603 is a ferromagnet that can have magnetization in +/- x, y, and z directions. For example, magnet 603 is a 6-state magnet as described with reference to Fig. 5. As such, magnet 603 can inject spins into spin orbit coupling layers 608 and 909 (same as layer 808 by material construction) causing charge currents in the +/- x, y, and z directions. Here, interconnect 606b is re-labeled interconnect 906b to show that it is coupled to SOC material 608 and not to SOC material 909. In some embodiments, the gap 901 between SOC materials 608 and 909 is oxide (like oxide 605). In some embodiments, via 607 is coupled to layers of SOC materials 608 and 909.

[0090] In some embodiments, interconnect 606a provides current hi which represents current associated with magnetization detected by FM 603 in the +/- x-direction, interconnect 606c provides current hi which represents current associated with magnetization detected in the +/- y-direction, and interconnect 906b provides current 7 _C 3 which represents current associated with magnetization detected in the +/- z-direction. Fig. 9B illustrates a top view 920 of a cross-section BB of the sensor of Fig. 9A, according to some embodiments of the disclosure.

[0091] Fig. 10 illustrates a smart device or a computer system or a SoC (System-on-

Chip) with a magnetic memory hard-disk drive (HDD) using 2-state, 4-state or 6-state magnets which can be sensed by the magnetic field sensor, according to some embodiments. It is pointed out that those elements of Fig. 10 having the same reference numbers (or names) as the elements of any other figure can operate or function in any manner similar to that described, but are not limited to such.

[0092] For purposes of the embodiments, the transistors in various circuits and logic blocks described here are metal oxide semiconductor (MOS) transistors or their derivatives, where the MOS transistors include drain, source, gate, and bulk terminals. The transistors and/or the MOS transistor derivatives also include Tri-Gate and FinFET transistors, Gate All Around Cylindrical Transistors, Tunneling FET (TFET), Square Wire, or Rectangular Ribbon Transistors, ferroelectric FET (FeFETs), or other devices implementing transistor functionality like carbon nanotubes or spintronic devices. MOSFET symmetrical source and drain terminals i.e., are identical terminals and are interchangeably used here. A TFET device, on the other hand, has asymmetric Source and Drain terminals. Those skilled in the art will appreciate that other transistors, for example, Bi-polar junction transistors (BJT PNP/NPN), BiCMOS, CMOS, etc., may be used without departing from the scope of the disclosure.

[0093] Fig. 10 illustrates a block diagram of an embodiment of a mobile device in which flat surface interface connectors could be used. In some embodiments, computing device 1600 represents a mobile computing device, such as a computing tablet, a mobile phone or smart-phone, a wireless-enabled e-reader, or other wireless mobile device. It will be understood that certain components are shown generally, and not all components of such a device are shown in computing device 1600.

[0094] In some embodiments, computing device 1600 includes first processor 1610 and network interface within 1670 such as a wireless interface so that a system embodiment may be incorporated into a wireless device, for example, cell phone or personal digital assistant.

[0095] In some embodiments, processor 1610 (and/or processor 1690) can include one or more physical devices, such as microprocessors, application processors,

microcontrollers, programmable logic devices, or other processing means. The processing operations performed by processor 1610 include the execution of an operating platform or operating system on which applications and/or device functions are executed. The processing operations include operations related to I/O (input/output) with a human user or with other devices, operations related to power management, and/or operations related to connecting the computing device 1600 to another device. The processing operations may also include operations related to audio I/O and/or display I/O.

[0096] In some embodiments, computing device 1600 includes audio subsystem

1620, which represents hardware (e.g., audio hardware and audio circuits) and software (e.g., drivers, codecs) components associated with providing audio functions to the computing device. Audio functions can include speaker and/or headphone output, as well as microphone input. Devices for such functions can be integrated into computing device 1600, or connected to the computing device 1600. In one embodiment, a user interacts with the computing device 1600 by providing audio commands that are received and processed by processor 1610.

[0097] In some embodiments, computing device 1600 comprises display subsystem

1630. Display subsystem 1630 represents hardware (e.g., display devices) and software (e.g., drivers) components that provide a visual and/or tactile display for a user to interact with the computing device 1600. Display subsystem 1630 includes display interface 1632, which includes the particular screen or hardware device used to provide a display to a user. In one embodiment, display interface 1632 includes logic separate from processor 1610 to perform at least some processing related to the display. In one embodiment, display subsystem 1630 includes a touch screen (or touch pad) device that provides both output and input to a user.

[0098] In some embodiments, computing device 1600 comprises I/O controller 1640.

I/O controller 1640 represents hardware devices and software components related to interaction with a user. I/O controller 1640 is operable to manage hardware that is part of audio subsystem 1620 and/or display subsystem 1630. Additionally, I/O controller 1640 illustrates a connection point for additional devices that connect to computing device 1600 through which a user might interact with the system. For example, devices that can be attached to the computing device 1600 might include microphone devices, speaker or stereo systems, video systems or other display devices, keyboard or keypad devices, or other I/O devices for use with specific applications such as card readers or other devices.

[0099] As mentioned above, I/O controller 1640 can interact with audio subsystem

1620 and/or display subsystem 1630. For example, input through a microphone or other audio device can provide input or commands for one or more applications or functions of the computing device 1600. Additionally, audio output can be provided instead of, or in addition to display output. In another example, if display subsystem 1630 includes a touch screen, the display device also acts as an input device, which can be at least partially managed by I/O controller 1640. There can also be additional buttons or switches on the computing device 1600 to provide I/O functions managed by I/O controller 1640.

[00100] In some embodiments, I/O controller 1640 manages devices such as accelerometers, cameras, light sensors or other environmental sensors, or other hardware that can be included in the computing device 1600. The input can be part of direct user interaction, as well as providing environmental input to the system to influence its operations (such as filtering for noise, adjusting displays for brightness detection, applying a flash for a camera, or other features).

[00101] In some embodiments, computing device 1600 includes power management

1650 that manages battery power usage, charging of the battery, and features related to power saving operation. Memory subsystem 1660 includes memory devices for storing information in computing device 1600. Memory can include nonvolatile (state does not change if power to the memory device is interrupted) and/or volatile (state is indeterminate if power to the memory device is interrupted) memory devices. Memory subsystem 1660 can store application data, user data, music, photos, documents, or other data, as well as system data (whether long-term or temporary) related to the execution of the applications and functions of the computing device 1600. In some embodiments, Memory subsystem 1660 includes the scheme of analog in-memory pattem matching with the use of resistive memory elements. In some embodiments, memory subsystem includes a magnetic memory HDD. This HDD can be formed using 2-state, 4-state or 6-state magnets which can be sensed by the magnetic field sensor, according to some embodiments

[00102] Elements of embodiments are also provided as a machine-readable medium (e.g., memory 1660) for storing the computer-executable instructions (e.g., instructions to implement any other processes discussed herein). The machine-readable medium (e.g., memory 1660) may include, but is not limited to, flash memory, optical disks, CD-ROMs, DVD ROMs, RAMs, EPROMs, EEPROMs, magnetic or optical cards, phase change memory (PCM), or other types of machine-readable media suitable for storing electronic or computer- executable instructions. For example, embodiments of the disclosure may be downloaded as a computer program (e.g., BIOS) which may be transferred from a remote computer (e.g., a server) to a requesting computer (e.g., a client) by way of data signals via a communication link (e.g., a modem or network connection).

[00103] In some embodiments, computing device 1600 comprises connectivity 1670.

Connectivity 1670 includes hardware devices (e.g., wireless and/or wired connectors and communication hardware) and software components (e.g., drivers, protocol stacks) to enable the computing device 1600 to communicate with external devices. The computing device 1600 could be separate devices, such as other computing devices, wireless access points or base stations, as well as peripherals such as headsets, printers, or other devices.

[00104] Connectivity 1670 can include multiple different types of connectivity. To generalize, the computing device 1600 is illustrated with cellular connectivity 1672 and wireless connectivity 1674. Cellular connectivity 1672 refers generally to cellular network connectivity provided by wireless carriers, such as provided via GSM (global system for mobile communications) or variations or derivatives, CDMA (code division multiple access) or variations or derivatives, TDM (time division multiplexing) or variations or derivatives, or other cellular service standards. Wireless connectivity (or wireless interface) 1674 refers to wireless connectivity that is not cellular, and can include personal area networks (such as Bluetooth, Near Field, etc.), local area networks (such as Wi-Fi), and/or wide area networks (such as WiMax), or other wireless communication. [00105] In some embodiments, computing device 1600 comprises peripheral connections 1680. Peripheral connections 1680 include hardware interfaces and connectors, as well as software components (e.g., drivers, protocol stacks) to make peripheral connections. It will be understood that the computing device 1600 could both be a peripheral device ("to" 1682) to other computing devices, as well as have peripheral devices ("from" 1684) connected to it. The computing device 1600 commonly has a "docking" connector to connect to other computing devices for purposes such as managing (e.g., downloading and/or uploading, changing, synchronizing) content on computing device 1600. Additionally, a docking connector can allow computing device 1600 to connect to certain peripherals that allow the computing device 1600 to control content output, for example, to audiovisual or other systems.

[00106] In addition to a proprietary docking connector or other proprietary connection hardware, the computing device 1600 can make peripheral connections 1680 via common or standards-based connectors. Common types can include a Universal Serial Bus (USB) connector (which can include any of a number of different hardware interfaces), DisplayPort including MiniDisplayPort (MDP), High Definition Multimedia Interface (HDMI), Firewire, or other types.

[00107] Reference in the specification to "an embodiment," "one embodiment," "some embodiments," or "other embodiments" means that a particular feature, structure, or characteristic described in connection with the embodiments is included in at least some embodiments, but not necessarily all embodiments. The various appearances of "an embodiment," "one embodiment," or "some embodiments" are not necessarily all referring to the same embodiments. If the specification states a component, feature, structure, or characteristic "may," "might," or "could" be included, that particular component, feature, structure, or characteristic is not required to be included. If the specification or claim refers to "a" or "an" element, that does not mean there is only one of the elements. If the specification or claims refer to "an additional" element, that does not preclude there being more than one of the additional element.

[00108] Furthermore, the particular features, structures, functions, or characteristics may be combined in any suitable manner in one or more embodiments. For example, a first embodiment may be combined with a second embodiment anywhere the particular features, structures, functions, or characteristics associated with the two embodiments are not mutually exclusive. [00109] While the disclosure has been described in conjunction with specific embodiments thereof, many alternatives, modifications and variations of such embodiments will be apparent to those of ordinary skill in the art in light of the foregoing description. The embodiments of the disclosure are intended to embrace all such alternatives, modifications, and variations as to fall within the broad scope of the appended claims.

[00110] In addition, well known power/ground connections to integrated circuit (IC) chips and other components may or may not be shown within the presented figures, for simplicity of illustration and discussion, and so as not to obscure the disclosure. Further, arrangements may be shown in block diagram form in order to avoid obscuring the disclosure, and also in view of the fact that specifics with respect to implementation of such block diagram arrangements are highly dependent upon the platform within which the present disclosure is to be implemented (i.e., such specifics should be well within purview of one skilled in the art). Where specific details (e.g., circuits) are set forth in order to describe example embodiments of the disclosure, it should be apparent to one skilled in the art that the disclosure can be practiced without, or with variation of, these specific details. The description is thus to be regarded as illustrative instead of limiting.

[00111] The following examples pertain to further embodiments. Specifics in the examples may be used anywhere in one or more embodiments. All optional features of the apparatus described herein may also be implemented with respect to a method or process.

[00112] Example 1 is a magnetic field sensor comprising: a magnet; a first layer comprising an inverse spin orbit coupling material, wherein the first layer is adjacent to the magnet; and a second layer comprising a non-magnetic metal, wherein the second layer is adjacent to the first layer.

[00113] Example 2 includes all features of example 1 , wherein the magnetic field sensor further comprises a first template layer between the magnet and the first layer.

[00114] Example 3 includes all features of example 2, wherein the magnetic field sensor further comprises: a second non-magnetic metal; and a second template layer between the magnet and the second non-magnetic metal.

[00115] Example 4 includes all features of example 3, wherein the magnetic field sensor further comprises: a via coupled to the first layer, and a third non-magnetic metal adjacent to the via.

[00116] Example 5 includes all features of example 4, wherein the non-magnetic metal is coupled to a current or voltage sensor, wherein second non-magnetic metal is coupled to a power supply node, and wherein the third non-magnetic metal is coupled to a ground node. [00117] Example 6 includes all features of example 4, wherein the magnetic field sensor further comprises: a fourth non-magnetic metal positioned parallel to the nonmagnetic metal and coupled to the first layer.

[00118] Example 7 includes all features of example 6, wherein the non-magnetic metal is to provide current associated with magnetization in a +/- x-direction, and wherein the second non-magnetic metal is to provide current associated with magnetization in a +/- y- direction.

[00119] Example 8 is according to any one of claims 1 to 7, wherein the magnetic field sensor further comprises: a third layer comprising a Rashba Bychkov material, wherein the third layer is to provide current associated with magnetization in a z-direction.

[00120] Example 9 includes all features of example 8, wherein the Rashba Bychkov material comprises a stack of materials which comprise two-dimensional (2D) materials with spin orbit interaction.

[00121] Example 10 includes all features of example 8, wherein the 2D materials include one or more of: Mo, S, W, Se, Graphene, M0S2, \VSe2, WS2, or MoSe2.

[00122] Example 11 includes all features of example 9, wherein the 2D materials include an absorbent which includes one or more of: Cu, Ag, Pt, Bi, Fr, or H absorbents.

[00123] Example 12 is according to any one of claims 1 to 7, wherein the magnet is a ferromagnet which is one of bi-axial magnet, four state magnet, or six state magnet.

[00124] Example 13 includes all features of example 12, wherein the four state magnet is configured to have four stable magnetic states including zero state, first state, second state, and third state, wherein the zero state is to point in a +x-direction, wherein the first state is to point in a +y-direction, wherein the second state is to point in a -y-direction, and wherein the third state is to point in a -x-direction.

[00125] Example 14 includes all features of example 12, wherein the six state magnet is configured to have six stable magnetic states including zero state, first state, second state, third state, fourth state, and fifth state, wherein the zero state is to point in a +x-direction, wherein the first state is to point in a +y-direction, wherein the second state is to point in a - y-direction, wherein the third state is to point in a -x-direction, wherein the fourth state is to point in a -z-direction, and wherein the fifth state is to point in a +z-direction.

[00126] Example 15 includes all features of example 12, wherein the six state magnet is one of: magnetostrictive ferromagnets adjacent to corresponding piezoelectric layers; tri- axial anisotropy magnets; or in-plane bi-axial anisotropy magnets adjacent to corresponding piezoelectric layers. [00127] Example 16 includes all features of example 12, wherein the bi-axial magnet has an out-of-plane magnetization and comprises of a stack of materials, wherein the materials for the stack include one or more of: Co and Pt; Co and Pd; Co and Ni; MgO, CoFeB, Ta, CoFeB, and MgO; MgO, CoFeB, W, CoFeB, and MgO; MgO, CoFeB, V, CoFeB, and MgO; MgO, CoFeB, Mo, CoFeB, and MgO; Mn _x Ga _y ; Materials with Llo symmetry; or materials with tetragonal crystal structure.

[00128] Example 17 includes all features of example 12, wherein the bi-axial magnet has an out-of-plane magnetization which comprises a single layer of one or more materials, and wherein the single layer comprises Mn and Ga.

[00129] Example 18 is according to any one of examples 1 to 7, wherein the magnet is a ferromagnet which comprises one or a combination of materials which include one of: a Heusler alloy, Co, Fe, Ni, Gd, B, Ge, Ga, permalloy, or Yttrium Iron Garnet (YIG).

[00130] Example 19 includes all features of example 18, wherein the Heusler alloy is a material which includes one or more of: Cu, Mn, Al, In, Sn, Ni, Sb, Ga, Co, Ge, Pd, Fe, V, Ru, Cu ₂ MnAl, Cu ₂ MnIn, Cu ₂ MnSn, Ni ₂ MnAl, Ni ₂ MnIn, Ni ₂ MnSn, Ni ₂ MnSb, Ni ₂ MnGa Co ₂ MnAl, Co ₂ MnSi, Co ₂ MnGa, Co ₂ MnGe, Pd ₂ MnAl, Pd ₂ MnIn, Pd ₂ MnSn, Pd ₂ MnSb, Co ₂ FeSi, Co ₂ FeAl, Fe ₂ VAl, Mn ₂ VGa, Co ₂ FeGe, MnGa, MnGaRu, or Mn ₃ X, where 'X' is one of Ga and Ge.

[00131] Example 20 is according to any one of examples 1 to 7, wherein first layer comprises a material which includes one of: β-Ta, β-W, W, Pt, Cu doped with Iridium, Cu doped with Bismuth, or Cu doped an element of 3d, 4d, 5d, 4f, or 5f of periodic table groups.

[00132] Example 21 is a system which comprises: a processor; a memory coupled to the processor, the memory comprising: a heat spreading layer; a transition metal layer adjacent to the heat spreading layer; and a magnetic recording layer adjacent to the transition metal layer, wherein a magnetic field sensor comprising an inverse spin orbit coupling material is to be positioned near enough to the magnetic recording layer to sense magnetic field from the magnetic recording layer; and a wireless interface to allow the processor to communicate with another device.

[00133] Example 22 includes all features of example 21, wherein the magnetic field sensor is according to any one of examples 1 to 20.

[00134] Example 23 includes all features of example 21, wherein the first transition metal layer is to produce a strain induced transition in the second transition metal layer. [00135] Example 24 includes all features of example 21, wherein the memory comprises a second transition metal layer adjacent to the magnetic recording layer such that the magnetic recording layer is between the first and second transition metal layers.

[00136] Example 25 includes all features of example 24, wherein the first or second transition metal layers comprises a material which includes of or more of: Co, Pt, Mo, Pd, Cr, and CoCrPt, wherein the Mo has a face centered cubic structure 1 10.

[00137] Example 26 includes all features of example 21 , wherein the memory comprises a glass substrate adjacent to the heat spreading layer.

[00138] Example 27 includes all features of example 21 , wherein the memory comprises a cladding layer adjacent to the magnetic recording layer, wherein the cladding layer comprises a material which includes one or more of: perfluoropoly ether (PFPE), Z- Type Perfluoro Poly Ether Lubricant Polymer, Z-Dol 4000, Z-Tetroal, ZDol 7800, or Cyclotriphosphazenes.

[00139] Example 28 includes all features of example 21, wherein the magnetic recording layer includes a plurality of magnetic components organized in an array configuration.

[00140] Example 29 includes all features of example 21, wherein the magnetic recording layer comprises a material which includes one or more of: Ru, Pt, or Pd.

[00141] Example 30 is a method which comprises: forming a magnet; forming a first layer comprising an inverse spin orbit coupling material, wherein the first layer is adjacent to the magnet; and forming a second layer comprising a non-magnetic metal, wherein the second layer is adjacent to the first layer.

[00142] Example 31 includes all features of example 30, wherein the method of example 31 comprises: forming a first template layer between the magnet and the first layer.

[00143] Example 32 includes all features of example 31, wherein the method of example 31 comprises: forming a second non-magnetic metal; and forming a second template layer between the magnet and the second non-magnetic metal.

[00144] Example 33 includes all features of example 32, wherein the method of example 31 comprises: forming a via coupled to the first layer, and forming a third nonmagnetic metal adj acent to the via.

[00145] Example 34 includes all features of example 34, wherein the non-magnetic metal is coupled to a current or voltage sensor, wherein second non-magnetic metal is coupled to a power supply node, and wherein the third non-magnetic metal is coupled to a ground node. [00146] Example 35 includes all features of example 34, wherein the method of example 31 comprises: forming a fourth non-magnetic metal positioned parallel to the nonmagnetic metal and coupled to the first layer.

[00147] Example 36 includes all features of example 36, wherein the non-magnetic metal is to provide current associated with magnetization in a +/- x-direction, and wherein the second non-magnetic metal is to provide current associated with magnetization in a +/- y- direction.

[00148] Example 37 includes all features of example 30, wherein the method of example 31 comprises: forming a third layer comprising a Rashba Bychkov material, wherein the third layer is to provide current associated with magnetization in a z-direction.

[00149] Example 38 includes all features of example 37, wherein the Rashba Bychkov material comprises a stack of materials which include two-dimensional (2D) materials with spin orbit interaction.

[00150] Example 39 includes all features of example 38, wherein the 2D materials include one or more of: Mo, S, W, Se, Graphene, M0S2, \VSe2, WS2, or MoSe2.

[00151] Example 40 includes all features of example 38, wherein the 2D materials include an absorbent which includes one or more of: Cu, Ag, Pt, Bi, Fr, or H absorbents.

[00152] Example 41 includes all features of example 30, wherein the magnet is a ferromagnet which is one of bi-axial magnet, four state magnet, or six state magnet.

[00153] Example 42 includes all features of example 41, wherein the four state magnet is configured to have four stable magnetic states including zero state, first state, second state, and third state, wherein the zero state is to point in a +x-direction, wherein the first state is to point in a +y-direction, wherein the second state is to point in a -y-direction, and wherein the third state is to point in a -x-direction.

[00154] Example 43 includes all features of example 41, wherein the six state magnet is configured to have six stable magnetic states including zero state, first state, second state, third state, fourth state, and fifth state, wherein the zero state is to point in a +x-direction, wherein the first state is to point in a +y-direction, wherein the second state is to point in a - y-direction, wherein the third state is to point in a -x-direction, wherein the fourth state is to point in a -z-direction, and wherein the fifth state is to point in a +z-direction.

[00155] Example 44 includes all features of example 41, wherein the six state magnet is one of: magnetostrictive ferromagnets adjacent to corresponding piezoelectric layers; u ⁿ iaxial anisotropy magnets; or in-plane bi-axial anisotropy magnets adjacent to corresponding piezoelectric layers. [00156] Example 45 includes all features of example 41, wherein the bi-axial magnet has an out-of-plane magnetization and comprises of a stack of materials, wherein the materials for the stack include one or more of: Co and Pt; Co and Pd; Co and Ni; MgO, CoFeB, Ta, CoFeB, and MgO; MgO, CoFeB, W, CoFeB, and MgO; MgO, CoFeB, V, CoFeB, and MgO; MgO, CoFeB, Mo, CoFeB, and MgO; Mn _x Ga _y ; Materials with Llo symmetry; or materials with tetragonal crystal structure.

[00157] Example 46 includes all features of example 41, wherein the bi-axial magnet has an out-of-plane magnetization which comprises a single layer of one or more materials, and wherein the single layer comprises Mn and Ga.

[00158] Example 47 includes all features of example 30, wherein magnet is a ferromagnet which comprises one or a combination of materials which include one or more of: a Heusler alloy, Co, Fe, Ni, Gd, B, Ge, Ga, permalloy, or Yttrium Iron Garnet (YIG).

[00159] Example 48 includes all features od example 47, wherein the Heusler alloy is a material which includes one or more of: Cu, Mn, Al, In, Sn, Ni, Sb, Ga, Co, Ge, Pd, In, Fe, V, Ru, Cu ₂ MnAl, Cu ₂ MnIn, Cu ₂ MnSn, Ni ₂ MnAl, Ni ₂ MnIn, Ni ₂ MnSn, Ni ₂ MnSb, Ni ₂ MnGa Co ₂ MnAl, Co ₂ MnSi, Co ₂ MnGa, Co ₂ MnGe, Pd ₂ MnAl, Pd ₂ MnIn, Pd ₂ MnSn, Pd ₂ MnSb, Co ₂ FeSi, Co ₂ FeAl, Fe ₂ VAl, Mn ₂ VGa, Co ₂ FeGe, MnGa, MnGaRu, and Mn ₃ X, where 'X' is one of Ga and Ge.

[00160] Example 49 includes all features of example 30, wherein first layer comprises a material which includes one or more of: β-Ta, β-W, W, Pt, Cu doped with Iridium, Cu doped with Bismuth, or Cu doped an element of 3d, 4d, 5d, 4f, or 5f of periodic table groups.

[00161] An abstract is provided that will allow the reader to ascertain the nature and gist of the technical disclosure. The abstract is submitted with the understanding that it will not be used to limit the scope or meaning of the claims. The following claims are hereby incorporated into the detailed description, with each claim standing on its own as a separate embodiment.