26 results about "Spin-transfer torque" patented technology

The invention provides a magnetic storage unit and device based on signal time delay. The unit comprises a first spin orbit moment layer and a first magnetic tunnel junction arranged on the first spin orbit moment layer. The distances between the first magnetic tunnel junction and the two ends of the first spin orbit moment layer are respectively a first distance and a second distance, and the first distance and the second distance are not equal; respectively inputting a first pulse signal and a second pulse signal from two ends of the first spin orbit moment layer along the first distance and the second distance; and the first pulse signal and the second pulse signal form a first write-in spin transfer torque current at the first magnetic tunnel junction due to signal time delay, so that the magnetic moment of a free layer of the first magnetic tunnel junction is subjected to deterministic overturning under the action of the first write-in spin transfer torque current. Deterministic writing of the magnetic tunnel junction can be realized without an additional auxiliary magnetic field, the device structure is simplified, and the area and power consumption overhead are reduced.

The invention discloses a true random number generator and a chip. The true random number generator comprises a phase-locked loop module and a trigger module, wherein the phase-locked loop module comprises a spin torque nano oscillation unit. The input end of the phase-locked loop module is used for receiving a reference signal, and the output end of the phase-locked loop module is connected with the trigger module. The phase-locked loop module is used for obtaining an output signal based on the spin transfer torque effect of the spin torque nano oscillation unit according to the reference signal and a feedback signal, and the feedback signal is a signal obtained by feeding back the output signal to the input end. The trigger module is used for sampling the output signal based on the reference signal to generate a random number sequence. Therefore, the random number sequence with high randomness can be generated, the influence of sampling and external magnetic field interference on the random number sequence is eliminated, and the robustness of the true random number generator is enhanced.

The present disclosure relates to magnetic devices such as magnetic transistors and magnetic memories that are regulated by magnetic spin transfer torque. According to one embodiment, a magnetic device based on magnetic spin transfer torque can include a first spin Hall effect layer, a first ferromagnetic insulating layer formed on the first spin Hall effect layer, an anti-ferromagnetic insulating layer formed on the first ferromagnetic insulating layer, a second ferromagnetic insulating layer formed on the anti-ferromagnetic insulating layer, and a second spin Hall effect layer formed on the second ferromagnetic insulating layer.

The present invention discloses a multifunctional racetrack design experimental method based on ferromagnetic skyrmions, comprising the following steps: first, constructing a racetrack using photolithography technology; second, setting a magnetic tunnel junction; third, performing logical operations of an AND gate and an OR gate; fourth, performing logical operations of a NOT gate; and fifth, performing operations on a unidirectional transmission function of a diode. The test racetrack of the present invention integrates the operational functions of an AND gate, an OR gate, a NOT gate, and a diode, thereby being multifunctional and having a wider scope of application. Furthermore, the racetrack of the present invention has low energy consumption, a small structural space, and is easy to integrate into a high-density spintronic device. Furthermore, the racetrack has high accuracy and strong non-volatility, and is driven by spin transfer torque, thus being highly subjectively controllable and suitable for promotion.

A memory array includes a word lines intersecting bit line-complementary bit line pairs at a plurality of cell locations. Magnetic tunnel junction cells are located at each location, and each cell is electrically connected to a corresponding bit line and selectively interconnected to a corresponding one of the complementary bit lines under control of a corresponding one of the word lines. Each cell includes a substrate; a seed layer overlying the substrate; a nitride layer, overlying the seed layer, and having a thickness greater than 5 Angstroms; a templating layer, outward of the nitride layer, including a binary alloy having an alternating layer lattice structure, and having a thickness greater than 50 Angstroms; a magnetic layer overlying the templating layer, including a Heusler compound and exhibiting PMA; a tunnel barrier outward of the magnetic layer; and a magnetic layer outward of the tunnel barrier.

The present embodiments relate to a perpendicular magnetic recording (PMR) write head with an STO element and configured to direct an electric current between elements of the write head. A first example embodiment describes a perpendicular magnetic recording (PMR) write head. The PMR write head can include a main pole comprising a tip portion disposed adjacent to an air bearing surface (ABS) and is configured to interact with a magnetic recording medium. The PMR write head can also include a spin torque oscillator (STO) element disposed adjacent to the main pole. The PMR write head can also include a side shield layer with a portion of the side shield layer disposed adjacent to the ABS. The PMR write head can also include a metallic side gap layer disposed between the main pole and the side shield layer.

The invention provides a spin transfer torque storage bit and a read-write method, and the spin transfer torque storage bit comprises a spin current control layer and a tunnel junction, the tunnel junction and the spin current control layer are sequentially arranged in the direction away from the substrate; before writing, the magnetization intensity direction of the spin current control layer is adjusted to a first direction based on a preset circuit, and the critical flip current of the tunnel junction is reduced; and before reading, the magnetization intensity direction of the spin current control layer is adjusted to a second direction based on the circuit, and the critical flip current of the tunnel junction is improved. According to the technical scheme provided by the invention, the problems that the critical write-in current cannot be reduced and the read-out reliability cannot be improved at the same time in the prior art and other problems caused by the problems are solved.

The present embodiments relate to write heads implementing microwave-assisted magnetic recording utilizing multiple spin torque oscillators (STOs). Each STO can include a field-generation layer (FGL) that can oscillate in a same frequency and out of phase with one another. The layers in each STO can enable mutual spin transfer torques between adjacent layers, which can drive the FGLs into a large angle oscillation. The oscillation between the FGLs can cause a magnetic field to be generated that can assist in writing to a magnetic recording medium.

A MRAM device utilizing spin transfer torque includes a substrate; an MTJ formed over the substrate, the MTJ including a reference layer, a tunnel barrier layer, and a free layer; and a PSM layer formed over the free layer of the MTJ. The PSM layer, i.e., a chiral material layer, may be formed adjacent to a free layer (or adjacent to a TBL, which is adjacent to the free layer) of the MTJ, providing an additional source of spin-transfer-torque, and providing MTJ devices that are operable with lower switching current.

The invention relates to a data read-write method and device based on a field-free flipping magnetic tunnel junction device structure, and the method comprises the steps: a heavy metal layer, a free layer and an oxide layer are expanded on the basis of a conventional magnetic tunnel junction, and a control side structure composed of an electrode layer is constructed on the basis; the reading side framework is composed of a reference ferromagnetic layer, a pinning layer and an electrode layer; when the information is written, the auxiliary voltage is applied to the current of the heavy metal layer of the control side framework to complete field-free overturning, so that the information is written; when information is read, the state of the magnetic moment of the free layer is read through the reading side framework according to the magnitude of current. Therefore, the problems that in a magnetic tunnel junction of a traditional voltage-controlled anisotropy design, a voltage signal is directly applied to an oxide layer through a reading electrode of the magnetic tunnel junction, spin-transfer torque current is generated, and the control effect of voltage-controlled anisotropy is weakened are solved.

A neuromorphic computing array includes horizontal lines and vertical lines, with the vertical lines intersecting the horizontal lines at cell locations. Magnetic tunnel junction cells are located at the cell locations. Each cell is electrically connected to a corresponding horizontal line and a corresponding vertical line. Each cell includes a substrate (1401), a seed layer (1403) covering the substrate, and a nitride layer (1403A) covering the seed layer (optionally, the nitride layer has a thickness greater than 5 angstroms). Each cell also includes a template layer (1403B) located outside the nitride layer, the template layer comprising a binary alloy having an alternating layered lattice structure and having a thickness greater than 50 angstroms. Each cell also includes a first magnetic layer (1405) covering the template layer, a tunnel barrier (1409) located outside the first magnetic layer, and a second magnetic layer (1411) located outside the tunnel barrier. The first magnetic layer (1405) comprises a Hessler alloy and exhibits perpendicular magnetic anisotropy (PMA).

Methods and apparatus are provided for an MRAM device utilizing spin transfer torque. A device includes: a substrate; an MTJ formed over the substrate, the MTJ including a reference layer, a tunnel barrier layer, and a free layer; and a PSM layer formed over the free layer of the MTJ. In some embodiments, a PSM layer (i.e., a chiral material layer) may be formed adjacent to a free layer of the MTJ (or adjacent to a TBL, the TBL being adjacent to the free layer), providing an additional source of spin transfer torque and providing MTJ devices that can operate with lower switching currents.

The invention provides a magnetic tunnel junction thin film, and the thin film comprises a magnetic tunnel junction lamination layer which comprises a reference layer, a barrier layer and a free layer, the first magnetic enhancement layer is arranged on the surface, away from the barrier layer, of the free layer, and the first magnetic enhancement layer is made of metal halide. According to the magnetic tunnel junction thin film provided by the invention, the vertical magnetic anisotropy of the magnetic tunnel junction can be enhanced on the premise that the tunnel magnetoresistance effect and the spin transfer torque effect are not influenced.

A method for forming structures with desired crystallinity used in MRAM applications is disclosed. Embodiments of the disclosure provide methods and apparatus for fabricating magnetic tunnel junction (MTJ) structures used in spin transfer torque magnetoresistive random access memory (STT-MRAM) applications on a substrate. In one embodiment, the method includes patterning a film stack disposed on a substrate having a tunneling barrier disposed between a magnetic reference layer and a magnetic storage layer to remove a portion of the film stack from the substrate until an upper surface of the substrate is exposed; forming a sidewall passivation layer on sidewalls of the patterned film stack; and subsequently performing a thermal anneal process on the film stack.

A spin transfer torque (STT) magnetoresistive memory cell includes a magnetic tunnel junction including a reference layer, a free layer, and a nonmagnetic tunnel barrier located between the reference layer and the free layer, and perpendicular exchange bias layer in contact with the free layer.

The invention discloses a magnetic storage array and a read-write method, in the magnetic storage array, a plurality of magnetic storage devices are arranged along an X-Y plane, and each word line simultaneously wraps the outer sides of a plurality of gates; each bit line is connected with the tops of the plurality of column electrodes; drain electrodes of the plurality of CMOS transistors are connected with the bottom of the column electrode; the grid line is connected with grid electrodes of the plurality of CMOS transistors; the source line is connected with the source electrodes of the plurality of CMOS transistors; magnetization overturning of a magnetic free layer of the magnetic tunnel junction is completed through the combined action of a spin-orbit moment and a spin-transfer moment, the spin-orbit moment is provided by spin-polarized electrons, the polarization direction of the spin-polarized electrons is the circumferential direction, generated by current passing through a column electrode, and the spin-transfer moment is provided by injecting write current in the radial direction of the magnetic tunnel junction. The judgment of the resistance state of the magnetic tunnel junction in the magnetic storage array is completed by injecting read current along the radial direction of the magnetic tunnel junction.

The present application discloses a magnetic pulse neuron device and its application. The device comprises: a magnetic tunnel junction for emitting a spike pulse electrical signal in response to a driving electrical signal. The magnetic tunnel junction comprises a capping layer, a magnetic free layer, a barrier layer, a pinning layer, and an antiferromagnetic layer stacked in sequence, with the magnetization direction of the magnetic free layer being in-plane oriented; a first electrode layer; a second electrode layer; and a high thermal resistance interface formed between the capping layer and the magnetic free layer. The high thermal resistance interface is configured to generate a thermally driven spin transfer torque and thermal noise under the action of the driving electrical signal. The magnetization direction of the magnetic free layer continuously flips under the action of the thermally driven spin transfer torque and the electrically driven spin transfer torque generated by the driving electrical signal. The magnetic pulse neuron device of the present application can generate a modulated spike pulse signal under the excitation of an external DC voltage or a pulse voltage, significantly saving area and reducing power consumption.

The invention provides a magnetic memory cell, comprising: a magnetic tunnel junction stack having a first surface and a second surface opposite to each other; the spin orbit moment layer is provided with a third surface and a fourth surface which are opposite to each other, and the first surface is electrically connected with the third surface; the first electrode is electrically connected with the second surface; the second electrode is electrically connected with the fourth surface, and the first electrode and the second electrode are arranged in a spaced mode in the horizontal direction. According to the magnetic storage unit and the preparation method thereof provided by the invention, the combined action of spin orbit torque and spin transfer torque can be realized by adopting a two-end structure, and meanwhile, the area required by the magnetic storage unit is reduced.

The application discloses a magnetic memory, which comprises a magnetic spin valve, a coupling layer and a magnetic tunnel junction from top to bottom; the magnetic spin valve comprises a spin reference layer, a non-magnetic spacer layer and a spin free layer from top to bottom; the magnetic tunnel junction comprises a tunnel free layer, a barrier layer and a tunnel reference layer from top to bottom; the magnetic tunnel junction is magnetically coupled with the magnetic spin valve through the coupling layer. The magnetic spin valve of the application provides an additional spin transfer torque for the magnetic memory, greatly improves the STT efficiency, drives the magnetic memory to flip using a smaller current, and further significantly reduces the power consumption of the magnetic memory. In addition, the magnetic spin valve has a smaller influence on the tunnel magnetoresistance of the whole device, so that the device can still maintain a high tunnel magnetoresistance. The application also provides an electronic device with the above beneficial effects.

The application relates to a multistate magnetic memory based on a double-layer magnetic tunnel junction, which comprises a top electrode (10), a first magnetic tunnel junction, a metal interlayer (50), a second magnetic tunnel junction, and a bottom electrode (90); wherein the first magnetic tunnel junction comprises, from top to bottom, a free layer FL1 (20), a tunneling layer (30), and a reference layer RL1 (40), the second magnetic tunnel junction comprises, from top to bottom, a free layer FL2 (60), a tunneling layer (70), and a reference layer RL2 (80); the memory is further provided with at least three ports, a port one (1) is connected with the top electrode (10), a port two (2) and a port three (3) are respectively arranged at the left and right ends of the bottom electrode (90), and the current direction of the port two is opposite to the current direction of the port three. The application simultaneously utilizes spin transfer torque (STT) and spin orbit torque (SOT) flip mechanisms, corresponding input current channels are independent, and write or read signals are inputted without affecting each other. The application introduces the magnetization flip of the reference layer, increases data writing space, and provides logical judgment for reading data bits.

The present invention discloses a dual-layer dynamic excitation mutual selection MPUF circuit and a dynamic excitation mutual selection MPUF generation method for resisting machine learning attacks. When either a first selection excitation module or a second selection excitation module is used as the excitation module, the other serves as the response module. The excitation module inputs an excitation signal to the corresponding spin-transfer torque-magnetic random access memory array. The discharge path port of the corresponding pre-charge sense amplifier circuit selects two discharge paths from the corresponding spin-transfer torque-magnetic random access memory array for comparison, generates a response signal, and inputs it into an obfuscated decoder circuit. This generates an excitation signal for the response module. The discharge path port of the pre-charge sense amplifier circuit corresponding to the response module selects two discharge paths from the corresponding spin-transfer torque-magnetic random access memory array based on the excitation signal generated by the response module for comparison, and outputs the comparison result. The present invention improves resistance to machine learning attacks, thereby enhancing safety during use.

The present disclosure is applicable to the technical field of spintronics. Provided is a spin transfer torque-based spin micro system. The system comprises a spin sensor device, which is configured to sense an external magnetic field and an external microwave signal, convert the external magnetic field and the external microwave signal into an electrical signal, and output same to a spin storage device; a spin logic device, which is configured to generate a first spin current to perform logic operation on the electric signal to obtain magnetic field information about the external magnetic field and microwave information about the external microwave signal, and output the magnetic field information and the microwave information to the spin storage device; a spin storage device, which is configured to receive the electric signal, the magnetic field information and the microwave information, generate a second spin current to output the electric signal to the spin logic device, and output the magnetic field information and the microwave information to a spin oscillator device; and a spin oscillator device, which is configured to receive the magnetic field information and the microwave information and generate a third spin current to convert the magnetic field information and the microwave information into an output microwave signal.

The invention discloses a no-reference single-ended read circuit based on a spin-transfer torque magnetic random access memory. The circuit comprises a bit line partial voltage generation circuit, a voltage-current sensing circuit and a current-voltage latch circuit. The memory unit is composed of a magnetic tunnel junction and a memory access transistor, the circuit does not need a reference unit during reading, data is pre-stored in the latch circuit, different partial voltages are generated on a bit line according to different resistance states of the magnetic tunnel junction, the partial voltages of the bit line are converted into current mirror input current, and the current mirror input current is converted into current mirror output current. And the magnitude of the output current of the current mirror determines that the latch state of the latch circuit is kept or overturned, so that the reading of the storage data of the storage unit is completed. The circuit can realize data reading under low voltage and high frequency, the power consumption is remarkably reduced in a current mode, the reading speed is increased, and the integration level is improved.

The invention discloses a spin valve device based on ferroelectric metal. The spin valve device comprises a top electrode, a first ferromagnetic layer, a ferroelectric metal layer, a second ferromagnetic layer and a bottom electrode which are sequentially stacked from top to bottom. Wherein the ferroelectric metal layer has ferroelectricity and metal conductivity at the same time, and is in direct contact with the upper ferromagnetic layer and the lower ferromagnetic layer to form an interface magnetoelectric coupling effect. Based on the core structure, the invention provides two nonvolatile memories, namely an STT type memory and an SOT type memory, the STT type memory performs writing by utilizing a spin-transfer torque effect, and the SOT type memory performs writing on a bottom heavy metal layer by utilizing a spin-orbit torque effect. Voltage pulses are applied to the ferroelectric metal layer to regulate and control the polarization state of the ferroelectric metal layer, so that magnetization overturning of the second ferromagnetic layer can be effectively assisted to reduce write-in power consumption; different polarization states of the ferroelectric metal layer are combined with different magnetization states of the ferromagnetic layer, so that a plurality of distinguishable resistance states can be formed, and multi-state information storage is realized.

The present embodiments relate to a perpendicular magnetic recording (PMR) write head with an STO element and configured to direct an electric current between elements of the write head. A first example embodiment describes a perpendicular magnetic recording (PMR) write head. The PMR write head can include a main pole comprising a tip portion disposed adjacent to an air bearing surface (ABS) and is configured to interact with a magnetic recording medium. The PMR write head can also include a spin torque oscillator (STO) element disposed adjacent to the main pole. The PMR write head can also include a side shield layer with a portion of the side shield layer disposed adjacent to the ABS. The PMR write head can also include a metallic side gap layer disposed between the main pole and the side shield layer.

The present embodiments relate to write heads implementing microwave-assisted magnetic recording utilizing multiple spin torque oscillators (STOs). Each STO can include a field-generation layer (FGL) that can oscillate in a same frequency and out of phase with one another. The layers in each STO can enable mutual spin transfer torques between adjacent layers, which can drive the FGLs into a large angle oscillation. The oscillation between the FGLs can cause a magnetic field to be generated that can assist in writing to a magnetic recording medium.