50 results about "Spin polarization" patented technology

The application belongs to the field of material calculation simulation, and relates to a prediction method for magnetic coupling evolution characteristics of two-dimensional Janus materials based on first principles. The technical problem to be solved is that the existing technology fails to uniformly analyze the magnetic freedom and structural evolution behavior, resulting in interlayer abnormal shrinkage, spontaneous bond collapse and lack of judgment basis for the coupling relationship between magnetism and interlayer structure. The technical scheme comprises the following steps: establishing a crystal structure model taking MA2Z4 material as a mother body; cutting and constructing an asymmetric Janus single layer; constructing a double-layer AA stacking initial model; performing geometric structure optimization and static self-consistent calculation under non-spin polarization and spin polarization conditions respectively; comparing the interlayer spacing, magnetic moment distribution and electronic state characteristics under the two conditions; analyzing the inhibitory effect of interface magnetism on interlayer bonding tendency by combining the electron localization function and the crystal orbital Hamiltonian population; and finally establishing the cooperative evolution relationship among magnetism, interlayer coupling and electronic structure, thereby providing a theoretical basis for identifying stable double-layer van der Waals configuration.

The utility model relates to the technical field of sensors, in particular to a three-dimensional magnetic sensor based on spin orbit moment, which comprises a packaging shell and a sensor chip packaged in the packaging shell. Compared with the prior art, the utility model has the following advantages: the heat radiation fins are arranged on the side wall of the packaging shell, so that the heat radiation area is effectively increased, the heat radiation is accelerated, the stable performance of the sensor can still be maintained under the high-strength working condition, the service life is prolonged, and the sensor chip adopts a bottom-to-top stacked structure, so that the cost is reduced. Particularly, the combination of the spin-orbit coupling layer and the magnetic layer enables the sensor to respond to the change of an external magnetic field and detect the direction and the strength of the magnetic field through the change of magnetic moment, so that the accurate measurement of a three-dimensional magnetic field is realized, and the magnetic layer is prepared into a circular or annular shape, thereby facilitating the uniform distribution of the magnetic field. And the buffer layer is arranged between the magnetic layer and the spin-orbit coupling layer, so that the transmission efficiency of the spin-polarized current is improved.

A columnar three-dimensional magnetic storage unit and a writing method are disclosed. In the magnetic storage unit, a central nanopillar is a nanopillar structure made of a material having a spin-orbit coupling effect; a magnetic storage layer wraps an outer side of the central nanopillar; a magnetic free layer surrounds and contacts the central nanopillar, with a polarization direction of the magnetic free layer extending axially along the nanopillar structure, and the magnetization reversal of the magnetic free layer depending on spin-polarized electrons, whose polarization direction is circumferential, generated by the central nanopillar, a damping-like torque and a field-like torque generated by the spin-polarized electrons synergistically achieving the magnetization precessional reversal of the magnetic free layer; a magnetic tunneling layer wraps an outer side of the magnetic free layer; a magnetic pinned layer wraps an outer side of the magnetic tunneling layer.

The application discloses a spin terahertz emitter and a chiral regulation method and a preparation method thereof, and belongs to the field of terahertz emission. The spin terahertz emitter is a three-layer structure including a ferromagnetic material layer, a non-ferromagnetic material layer and an antiferromagnetic layer. The antiferromagnetic layer adopts a preset crystal phase NiO single crystal antiferromagnetic material, CrSb or Mn3Sn. Under the irradiation of a femtosecond laser, the antiferromagnetic layer generates a laser impact magnetic moment. The precession of the laser impact magnetic moment generates a spin polarization current. The spin polarization current is injected into the non-ferromagnetic layer to generate a transient charge current, and then radiate terahertz, thereby realizing efficient spin terahertz radiation. Further, the magnetic moment direction of the ferromagnetic material layer in the spin terahertz emitter is reversed by rotating the direction of an external magnetic field or by a spin-orbit moment effect, thereby realizing efficient regulation of terahertz chirality.

This invention relates to the field of magnetic electronic devices, and more particularly to a magnetic tunnel junction, its fabrication method, and its applications. The magnetic tunnel junction includes: a lower electrode layer, a tunneling barrier layer, and an upper electrode layer; the tunneling barrier layer is disposed between the upper and lower electrode layers; wherein the tunneling barrier layer includes a self-supporting hafnium zirconium oxide film; the thickness of the self-supporting hafnium zirconium oxide film is 1-3 nm. The fabrication of this magnetic tunnel junction includes: firstly, growing an ultrathin LSMO / HZO bilayer structure on a substrate using PLD; utilizing LSMO as a sacrificial layer that can be selectively removed by a mixed solution of HCl and KI to release HZO in a self-supporting form; then, attaching the HZO to an FGT electrode to finally form the magnetic tunnel junction. The magnetic tunnel junction provided by this invention exhibits a tunneling magnetoresistance ratio (TMR) of approximately 140% at 2 K, indicating that the combination of this ultrathin ferroelectric barrier and the two-dimensional ferromagnetic electrode can achieve significant spin-polarized tunneling.

The application relates to a chiral spin-polarized circularly polarized light photoelectric device, preparation and application, and belongs to the technical field of optoelectronic devices. Specifically, a chiral molecule is introduced on the surface of a semiconductor, and a target of recognizing a light polarization state is realized by using spin polarization induced by a chiral structure. The chiral molecule will generate a Rashba-like spin-orbital coupling effect on the surface through spin exchange interaction, causing symmetry breaking, so as to generate a circularly polarized photocurrent effect under external light conditions. Different chiral (-L / -D) structure molecules have different response effects on polarized light. The chiral spin-polarized optoelectronic device shown in the application has a remarkable circularly polarized light detection effect, the experimental operation is simple and easy to implement, the device preparation cost is low, and the application of the chiral structure in a spin photoelectric device can be greatly expanded.

This invention proposes a semiconductor laser device with a spin-polarized sublayer, comprising, from bottom to top, a substrate, a lower confinement layer, a lower waveguide layer, an active layer, an upper waveguide layer, and an upper confinement layer. This invention establishes a multi-layered spin-polarized sublayer structure between the upper confinement layer and the upper waveguide layer in the semiconductor laser device, and defines the electron mobility distribution and piezoelectric polarization coefficient distribution characteristics of each spin-polarized sublayer. The specific electron mobility distribution and piezoelectric polarization coefficient distribution of the spin-polarized sublayer form an asymmetric discrete potential barrier, modulating the polarization of the lattice distortion structure, increasing the net accumulation of charge dipole momentum, controlling the piezoelectric polarization effect of the active layer, suppressing the quantum confinement Stark effect, reducing the band tilt of the active layer, reducing the hole injection band order, increasing the overlap probability of electron-hole wave functions, and improving the internal quantum efficiency.

The application discloses a kind of magnetic random memory based on nonlinear spin polarization and its implementation method, belong to magnetic random memory field.The spin orbit layer of the present application adopts magnetic material with perpendicular magnetic anisotropy, when writing, write current is applied in plane by writing electrode, due to nonlinear spin polarization effect, the magnetization vector of spin orbit layer is greatly periodic oscillation, after current is cut off, magnetization vector is determined to relax to the nearest steady state from current phase, information writing is realized;When reading, read circuit shows the voltage state corresponding to the state of magnetization vector, information reading is realized;The present application solves the problem of material symmetry restriction and process sensitivity faced by magnetic memory device when determining flip without external field.The present application widens material selection range, realizes the determining flip without external magnetic field, improves interface efficiency and write energy efficiency, and simplifies device process structure;The present application is applied to MRAM array design and peripheral integrated circuit.

The application discloses a magnetic tunnel junction and a magnetic memory, the magnetic tunnel junction comprising a spin orbit coupling layer, a free layer, a barrier layer, a reference layer and a pinned layer which are sequentially stacked; further comprising at least one magnetic layer, the at least one magnetic layer comprising a first spin polarization enhancement layer and / or a second spin polarization enhancement layer, the first spin polarization enhancement layer being located between the spin orbit coupling layer and the free layer, the magnetization direction of the first spin polarization enhancement layer being the same as that of the free layer; the second spin polarization enhancement layer being located between the reference layer and the pinned layer, the magnetization direction of the second spin polarization enhancement layer being the same as that of the reference layer. The magnetic tunnel junction provided by the application has improved tunneling magnetoresistance.

The invention discloses a geomagnetic field accurate measurement method and device based on optical detection helium-3, and the method comprises the steps: achieving nuclear spin polarization through optical pumping and metastable state spin exchange, applying a pulse magnetic field to excite a helium-3 nuclear spin FID signal, and detecting the frequency and relaxation rate of the helium-3 nuclear spin FID signal; a theoretical model is constructed, parameters such as helium 3 atomic number density and relaxation rate in a gas chamber are measured in combination with spin exchange frequency shift and a relaxation phenomenon, a conversion formula of FID frequency and helium 3 ground state Larmor frequency is established based on the parameters, and frequency shift caused by spin exchange is corrected; the residual magnetism of the probe is inversed through multi-angle measurement, errors introduced by the residual magnetism are eliminated, and finally accurate measurement of the geomagnetic field is achieved. The invention provides a geomagnetic field accurate measurement method and device based on optical detection helium-3, which are used for carrying out complete system error correction and elimination aiming at spin exchange and probe residual magnetism system errors in an optical detection type geomagnetic field helium-3 magnetometer, and can solve the problem that the accuracy and the sensitivity of geomagnetic field measurement are difficult to consider at the same time.

A kind of SERF biaxial magnetic field measuring device and method without magnetic field modulation, for the problem that modulation magnetic field needs to be applied in traditional biaxial measurement, leading to spin exchange relaxation increase and magnetic field crosstalk, it is proposed to replace the traditional magnetic field modulation by modulating the pumping light in SERF atomic magnetometer, then measure biaxial atomic spin polarizability information, realize biaxial magnetic field measurement.This method can realize higher sensitivity biaxial magnetic field measurement without introducing modulation magnetic field by abandoning the external modulation magnetic field in traditional biaxial measurement, and can completely suppress magnetic field crosstalk.Provide a new scheme for future new generation of ultra-high sensitivity array atomic magnetometer technology and application.

The application provides a SERF inertial measurement device nuclear spin lossless flip method, relates to the technical field of quantum precision measurement and inertial navigation, and lossless inverts the nuclear spin polarization direction by applying a specific radio frequency magnetic field to the SERF inertial measurement device. The frequency and amplitude of the applied radio frequency magnetic field change over time, so that the effective magnetic field experienced by the nuclear spin in the rotating coordinate system changes slowly from initially parallel to the polarization direction to the opposite polarization direction, thereby realizing lossless inversion of the nuclear spin polarization direction. The application has important significance for realizing online rapid measurement of nuclear polarization rate, developing a new type of inertial measurement output scheme and further suppressing system slow drift error.

Disclosed herein is a device using unconventional unidirectional magnetoresistance in layered heterostructures. The device consists of coupled layers of a material having out-of-plane spin polarization and a ferromagnet having perpendicular magnetic anisotropy (PMA) to read the up and down states of the PMA magnetic layer using longitudinal resistance measurements.

The invention discloses a spin electron polarizability determination method and related equipment, and the method comprises the steps: obtaining a state density function and a transmission coefficient of a spin polarization electron source, and determining a supply function according to the state density function; determining an energy distribution function according to the supply function and the transmission coefficient; and determining the current density according to the energy distribution function, and determining the spin electron polarizability according to the current density. The embodiment of the invention can reduce the calculation amount and improve the result accuracy. The invention can be widely applied to the technical field of electron polarization.

The invention provides a magnetic tunnel junction. The magnetic tunnel junction comprises a reference layer, a barrier layer and a free layer which are arranged in sequence, wherein the reference layer and the free layer are formed by staggered magnets, the included angle between the first crystal orientation of the staggered magnets and the tunneling direction is a first acute angle, and the reference layer and the free layer have local non-zero spin polarization in transverse momentum distribution obtained after integration in the inverted space momentum direction of the first crystal orientation. The average spin polarization on the transverse momentum distribution is zero; the barrier layer is made of a non-magnetic insulating material, the included angle between the second crystal orientation of the non-magnetic insulating material and the tunneling direction is a second acute angle, and the non-magnetic insulating material of the second crystal orientation and the staggered magnets of the first crystal orientation achieve lattice matching. According to the magnetic tunnel junction and the magnetic storage unit provided by the invention, the relatively high tunneling magnetoresistance effect of the staggered magnets under the specific crystal orientation can be utilized to ensure that the manufactured magnetic tunnel junction has a relatively large read window, and meanwhile, the characteristic that the magnetic tunnel junction does not express net magnetic moment to the outside can be utilized to avoid interference of an external magnetic field.

The invention discloses a high-precision rapid in-situ measurement device and method for polarization parameters of an atomic common magnetometer, and belongs to the technical field of quantum precision measurement and ultrahigh-sensitivity inertial measurement. Based on an atom manipulation technology, a transverse modulation magnetic field is applied to an atom ensemble through a three-axis magnetic field coil, a lock-in amplifier is adopted to extract device output phase frequency response, a longitudinal axis magnetic field is gradually scanned until the minimum phase frequency response is obtained, and therefore a nuclear spin polarization equivalent magnetic field and an electron spin polarization equivalent magnetic field are obtained. And further obtaining the electron spin polarizability, the nuclear spin polarizability and the nuclear spin longitudinal relaxation time. According to the invention, the rapid in-situ measurement of the atom ensemble polarization parameters of the SERF gyroscope is realized, and the measurement precision is improved.

The application provides a long-range ferromagnetic GaN material and a preparation method and application thereof. In the preparation method, the low temperature corresponding to the square wave pulse temperature is 500-700 DEG C, a stack mismatched wurtzite GaN structure layer is formed on a substrate during low-temperature deposition, the high temperature corresponding to the square wave pulse temperature is 800-1000 DEG C, a wurtzite structure GaN layer is deposited on the stack mismatched wurtzite GaN structure layer during high-temperature deposition, and the stack mismatched wurtzite GaN structure layer is buried. The stack mismatched grain boundary with long-range ferromagnetic sequence is formed in the GaN by controlling the temperature to change periodically in the square wave pulse, other magnetic impurities are not introduced, and the reaction chamber is not polluted. The energy band of the stack mismatched wurtzite GaN structure is simulated, the spin polarization property is confirmed to exist, on the basis, the Curie temperature is predicted according to the mean field approximation, and it is confirmed that the long-range magnetic sequence can still be kept under the condition that the temperature is higher than room temperature.

A method of measuring an external magnetic field using an atomic magnetometer comprises: using a polarized pump beam 1 to spin-polarise the atomic vapour; magnetising the polarized atomic vapour by a

The application provides a self-generated spin-orbital moment structure and a spin-orbital moment device, and belongs to the field of memory devices.The self-generated spin-orbital moment structure comprises a plurality of heavy metal layers and a plurality of ferromagnetic layers.The number of the heavy metal layers is one more than the number of the ferromagnetic layers, the plurality of heavy metal layers and the plurality of ferromagnetic layers are alternately stacked, each ferromagnetic layer is clamped between two heavy metal layers, and the adjacent heavy metal layers and ferromagnetic layers are in hetero-interface contact.The thickness of the plurality of heavy metal layers or the plurality of ferromagnetic layers is gradiently distributed along the stacking direction.The self-generated spin-orbital moment introduces a thickness gradient in the multilayer heavy metal layer or the ferromagnetic material layer, modulates the absorption and reflection spatial distribution of the spin polarization current in the multilayer ferromagnetic layer, and gradiently induces spin accumulation imbalance in the multilayer ferromagnetic layer to generate a net damping type SOT, so as to effectively balance the SOT generation efficiency and thermal stability of the self-generated spin-orbital moment structure.

The application relates to the technical field of primordial muon detection, and discloses a primordial muon spin polarization measurement system, which comprises a primordial muon momentum detection module, a primordial muon stopping target and a positron and electron detection module. The primordial muon momentum detection module is used for detecting the momentum information of a primordial muon passing through the primordial muon momentum detection module. The primordial muon stopping target is arranged below the primordial muon momentum detection module, and the axis of the primordial muon stopping target extends along a first direction. The positron and electron detection module is arranged below the primordial muon momentum detection module, and the positron and electron detection module comprises a first positron and electron detection unit group and a second positron and electron detection unit group. The first positron and electron detection unit group, the primordial muon stopping target and the second positron and electron detection unit group are sequentially and spacedly arranged along the first direction. The first positron and electron detection unit group and the second positron and electron detection unit group each comprise a plurality of positron and electron detection units which are sequentially arranged along the circumference of the axis of the primordial muon stopping target.

The invention provides an orbital moment magnetic memory and a preparation method thereof, the orbital moment magnetic memory comprises a substrate, an orbital Hall layer, a free layer, a barrier layer and a binding layer which are sequentially arranged from bottom to top, the orbital Hall layer comprises a metal layer and a FeMn layer which are arranged up and down, the free layer comprises a first Co2Fe6B2 layer and a Fe3GaTe2 layer which are arranged up and down, and the binding layer comprises a second Co2Fe6B2 layer and a second Fe3GaTe2 layer which are arranged up and down. And the bundling layer comprises a [Co / Pt] n layer, a Ta layer and a second Co2Fe6B2 layer which are arranged up and down. The structure utilizes the track Hall layer to efficiently generate a track flow, exchange a bias field and a stray field, and realizes spin polarization and magnetization flipping at the same time under low current through the strong spin-track coupling characteristic of the Fe3GaTe2 layer. According to the orbital moment magnetic memory, the power consumption is reduced while the relatively high writing speed is kept, the excellent performance is shown in high-speed data access, and basic support is provided for application in the fields of future orbital electronics, magnetic storage and the like.

The invention provides a three-dimensional stacked magnetic random access memory, a manufacturing method thereof and electronic equipment, and relates to the technical field of integrated circuits. The magnetic tunnel junction is formed by overlapping an alternating magnetic free layer, an insulating tunnel barrier layer and an alternating magnetic fixed layer, and the alternating magnetic free layer can regulate and control the alternating magnetic sequence of the alternating magnetic free layer by using a force applied by a magnetic moment of a spin-polarized electron current of the alternating magnetic fixed layer, so that the magnetization overturning of the magnetic tunnel junction is completed in a pure electrical mode; therefore, stable writing of data is realized under the action of current, so that the magnetic random access memory has the advantages of low power consumption, high speed and non-volatility. Moreover, according to the technical scheme provided by the invention, the anti-interference capability of the three-dimensional stacked magnetic memory is effectively improved by utilizing the advantage of strong anti-interference performance of the alternating magnet on an external magnetic field, so that large-area and high-density stacking of devices can be realized.

The application provides a spin-polarized current generator and a half-metallic material based on a anti-ferromagnetic material, and aims at solving the technical problem that the macroscopic ferromagnetic property of the existing two-dimensional layered material half-metallic material implementation method seriously affects the performance of the spin electronic device. In the application, non-magnetic metal atoms are deposited on the anti-ferromagnetic material, the spin of the partial atoms of the anti-ferromagnetic material on the non-magnetic insulating substrate is reversed, the original electron spin degeneracy of the anti-ferromagnetic material is destroyed, the anti-ferromagnetic material is converted into a ferromagnetic material, 100% spin polarization at the Fermi surface is realized, the anti-ferromagnetic material realizes the half-metallic material, and a voltage is applied on both sides of the non-magnetic insulating substrate, the spin-polarized electrons on the non-magnetic insulating substrate move in a direction, the output of the spin-polarized current is formed, the influence of the macroscopic ferromagnetic property on the spin electronic device is effectively avoided, and the technical difficulties that the two-dimensional material is cut into a strip and the doping atoms are positioned in experiments are avoided.

Aspects of the disclosure generally relate to a magnetic recording head of a magnetic media drive. In one example, the magnetic recording head includes a main pole, a back shield, and a spintronic device disposed between the main pole and the back shield. The spintronic device includes a negative polarization layer (NPL) disposed on the main pole, the NPL including FeTi, FeV, FeCr, or FeN; an interface layer disposed on the NPL, the interface layer including V, Cr, or Ru; a spacer layer disposed on the interface layer; and a spin torque layer (FGL) disposed on the spacer layer. When a current is applied to the spintronic device, the NPL and a first interface disposed between the NPL and the interface layer have a negative spin polarization, while the FGL and a second interface disposed between the FGL and the spacer layer have a positive spin polarization.

The invention provides a nuclear spin lossless inversion method for an SERF inertial measurement device, relates to the technical field of quantum precision measurement and inertial navigation, and aims to perform lossless inversion on a nuclear spin polarization direction by applying a specific radio frequency magnetic field to the SERF inertial measurement device. The frequency and amplitude of the applied radio frequency magnetic field change along with time, so that an effective magnetic field sensed by nuclear spin in a rotating coordinate system slowly changes from an initial parallel polarization direction to an anti-parallel polarization direction, thereby realizing lossless inversion of the nuclear spin polarization direction. The method provided by the invention is of great significance in realizing on-line rapid measurement of the nucleon polarizability, developing a novel inertial measurement output scheme and further suppressing the slow drift error of the system.

The invention provides a magneto-optical pulse regulation and control-based SERF (single-electron radio frequency) gyroscope coupling spinning rapid overturning method, relates to the technical field of inertial navigation and quantum precision measurement, and adopts the magneto-optical pulse regulation and control-based SERF gyroscope coupling spinning rapid overturning method. Through cooperative control of rapid switching of a pi pulsed magnetic field and pumping light polarization driven by an electro-optical modulator (EOM) in the SERF atomic spin gyroscope, efficient and rapid overturning of a coupling spin system composed of alkali metal electron spin and inert gas nuclear spin in a self-compensation working state is realized. The method is suitable for periodic control of coupling spin polarization in a high-precision atomic spin gyroscope and suppression of system low-frequency drift errors.

The invention discloses a magnetic random access memory. A rare earth element insertion layer is used for optimizing and improving the storage density, the anti-interference capability, the tunneling magnetoresistance and the spin polarizability of an STT-MRAM (Spin Transfer Torque Magnetic Random Access Memory) and an SOT-MRAM (Spin Object Transfer Magnetic Random Access Memory). The invention provides a magnetic random access memory, which comprises a magnetic tunnel junction, the magnetic tunnel junction comprises a tunneling layer made of MgO and a ferromagnetic free layer, the surface of the free layer is also provided with a rare earth layer, and the rare earth layer is composed of rare earth elements with 4f magnetic electrons. Due to the existence of the rare earth layer, the performance such as the storage density, the anti-interference capability, the tunneling magnetoresistance and the spin polarizability of the device is optimized.

The application discloses the technical field of two-dimensional magnetic material performance regulation and control, and relates to a two-dimensional magnetic semimetal material and a theoretical calculation method thereof. The two-dimensional magnetic semimetal material has a sandwich layer structure composed of a first selenium atom layer, a vanadium atom layer and a second selenium atom layer inherent to a single-layer vanadium diselenide, and an oxygen atom layer formed by adsorbing oxygen atoms on the first selenium atom layer and / or the second selenium atom layer. The two-dimensional material has a semimetal characteristic and a spin polarization rate of 100% through calculation by a software package VASP. The application provides a basis for preparation of the two-dimensional magnetic semimetal material and has a wide prospect in miniaturization application of spintronic devices, and has important significance for device research and development in the post-moore era.

A method for compensating and controlling the transverse magnetic field of inert gas nuclear spin under angular velocity input is proposed. First, a linear non-autonomous system model of the atomic spin ensemble is constructed, with the transverse magnetic field as the input and the unknown transverse angular velocity as the disturbance term. Then, a high-gain state observer is constructed to observe the transverse nuclear spin polarization intensity. Next, the magnetization constant is measured using the constructed high-gain state observer. Finally, a compensation controller is designed to generate a transverse magnetic field based on the observed transverse nuclear spin polarization intensity and apply it to the system to compensate for the transverse magnetic field generated by the nuclear spin under angular velocity input. This method achieves real-time measurement and compensation control of the transverse magnetic field of inert gas nuclear spin, is easy to implement in engineering, and is applicable to the field of atomic ensemble magnetic field measurement and control in atomic spin inertial measurement devices.

The present disclosure relates to a fixed layer of a magnetic tunnel junction, a magnetic storage chip, and a method for manufacturing the magnetic tunnel junction, and particularly provides a new MTJ device structure and a method for manufacturing the same. Specifically, fixed layers are prepared on both sides of a free layer of a conventional MTJ, i.e., forming a double-fixed-layer structure. The double-fixed-layer MTJ is made of ferromagnetic materials with high spin polarization rates that are subject to certain magnetization treatment, have a certain difference in coercivity strength and have opposite spin directions. The structure can realize for the first time that information writing energy can be reduced when spins of the fixed layers and the free layer of the MTJ change from parallel state to antiparallel state and from antiparallel state to parallel state.