Abstract: A magnetoresistive memory cell includes a first electrode, a second electrode that is spaced from the first electrode, a magnetic tunnel junction layer stack located between the first electrode and the second electrode, the magnetic tunnel junction layer stack containing, from one side to another, a reference layer having a fixed reference magnetization direction, a tunnel barrier layer comprising a dielectric material, and a free layer, and an asymmetric magnetoresistance layer located between the magnetic tunnel junction layer stack and one of the first electrode and the second electrode.

Abstract: Magnetoelectric or magnetoresistive memory cells may include a plurality of reference layers and optionally a plurality of free layers to enhance the tunneling magnetoresistance (TMR) ratio.

Abstract: A memory device includes a first electrode, a second electrode that is spaced from the first electrode, a fixed vertical magnetization structure configured to generate a fixed vertical magnetic field and located between the first electrode and the second electrode, at least one layer stack located between the fixed magnetization structure and the second electrode and containing respective spacer dielectric layer and a respective additional reference layer including a respective ferromagnetic material having perpendicular magnetic anisotropy, and a magnetic tunnel junction located between the at least one layer stack and the second electrode, the magnetic tunnel junction containing a reference layer, a free layer, and a nonmagnetic tunnel barrier layer located between the reference layer and the free layer, and the reference layer being more proximal to the at least one layer stack than the free layer is to the at least one layer stack.

Abstract: A memory device includes a first electrode, a second electrode that is spaced from the first electrode, a fixed vertical magnetization structure configured to generate a fixed vertical magnetic field and located between the first electrode and the second electrode, at least one layer stack located between the fixed magnetization structure and the second electrode and containing respective spacer dielectric layer and a respective additional reference layer including a respective ferromagnetic material having perpendicular magnetic anisotropy, and a magnetic tunnel junction located between the at least one layer stack and the second electrode, the magnetic tunnel junction containing a reference layer, a free layer, and a nonmagnetic tunnel barrier layer located between the reference layer and the free layer, and the reference layer being more proximal to the at least one layer stack than the free layer is to the at least one layer stack.

Abstract: A perpendicular spin transfer torque MRAM memory cell includes a magnetic tunnel junction stack comprising a pinned layer having a fixed direction of magnetization, a free layer having a direction of magnetization that can be switched, a tunnel barrier between the pinned layer and the free layer, a cap layer above the free layer and one or more in-stack multi-layer thermal barrier layers having multiple internal interfaces between materials. The thermal barrier layers have high enough thermal resistivity to maintain the heat generated in the memory cell and low enough electrical resistivity to not materially change the electrical resistance of the memory cell. One embodiment further includes a thermal barrier liner surrounding the free layer, pinned layer, tunnel barrier and cap layer.

Abstract: Disclosed herein are magnetic recording devices and methods of using them. A magnetic recording device comprises a main pole extending to an air-bearing surface (ABS), a trailing shield extending to the ABS, a write-field-enhancing structure disposed between and coupled to the main pole and the trailing shield at the ABS, a write coil configured to magnetize the main pole, a write current control circuit coupled to the write coil and configured to apply a write current to the write coil, wherein the write current comprises a write pulse, and a bias current control circuit coupled to the write-field-enhancing structure and configured to apply a bias current to the write-field-enhancing structure, wherein the bias current comprises a driving pulse offset in time from the write pulse by a delay, wherein the delay substantially coincides with an expected magnetization switch-time lag of a free layer of the write-field-enhancing structure.

Abstract: A MRAM memory cell comprises a SHE layer, a magnetic bit layer with perpendicular anisotropy and an Oersted layer. The magnetic bit layer has a switchable direction of magnetization in order to store data. Data is written to the MRAM memory cell using the Spin Hall Effect so that spin current generated in the SHE layer exerts a torque on the magnetic bit layer while the Oersted layer provides heat and an Oersted field to enable deterministic switching. Data is read form the MRAM memory cell using the Anomalous Hall Effect and sensing voltage at the Oersted layer.

Abstract: A perpendicular spin transfer torque MRAM memory cell includes a magnetic tunnel junction stack comprising a pinned layer having a fixed direction of magnetization, a free layer having a direction of magnetization that can be switched, a tunnel barrier between the pinned layer and the free layer, a cap layer above the free layer and one or more in-stack multi-layer thermal barrier layers having multiple internal interfaces between materials. The thermal barrier layers have high enough thermal resistivity to maintain the heat generated in the memory cell and low enough electrical resistivity to not materially change the electrical resistance of the memory cell. One embodiment further includes a thermal barrier liner surrounding the free layer, pinned layer, tunnel barrier and cap layer.

Abstract: A MRAM memory cell comprises a SHE layer, a magnetic bit layer with perpendicular anisotropy and an Oersted layer. The magnetic bit layer has a switchable direction of magnetization in order to store data. Data is written to the MRAM memory cell using the Spin Hall Effect so that spin current generated in the SHE layer exerts a torque on the magnetic bit layer while the Oersted layer provides heat and an Oersted field to enable deterministic switching. Data is read form the MRAM memory cell using the Anomalous Hall Effect and sensing voltage at the Oersted layer.

Abstract: A perpendicular spin transfer torque MRAM memory cell includes a magnetic tunnel junction that has a free layer, a pinned layer and a tunnel barrier between the free layer and the pinned layer. The free layer has a switchable direction of magnetization perpendicular to the plane of the free layer. A cap layer is provided adjacent to the magnetic tunnel junction. The thickness of the cap layer is increased so that the cap layer acts as a heating layer, which results in a reduction of the current density during writing and increases the write margin. In some embodiments, a resistive heating layer is added to the memory cell, adjacent to the cap layer, in order to achieve the lower current density and increased write margin while also improving signal to noise ration during reading by eliminating shot noise.

Abstract: Disclosed herein are magnetic recording devices and methods of using them. A magnetic recording device comprises a main pole extending to an air-bearing surface (ABS), a trailing shield extending to the ABS, a write-field-enhancing structure disposed between and coupled to the main pole and the trailing shield at the ABS, a write coil configured to magnetize the main pole, a write current control circuit coupled to the write coil and configured to apply a write current to the write coil, wherein the write current comprises a write pulse, and a bias current control circuit coupled to the write-field-enhancing structure and configured to apply a bias current to the write-field-enhancing structure, wherein the bias current comprises a driving pulse offset in time from the write pulse by a delay, wherein the delay substantially coincides with an expected magnetization switch-time lag of a free layer of the write-field-enhancing structure.

Abstract: A magnetoresistive random access memory (MRAM) memory cell comprises a pinned layer having fixed direction of magnetization that is perpendicular to a plane of the pinned layer, a first free layer having a direction of magnetization that can be switched and is perpendicular to a plane of the first free layer, a tunnel barrier positioned between the pinned layer and the first free layer, a second free layer having a direction of magnetization that can be switched, and a spacer layer positioned between the first free layer and the second free layer. Temperature dependence of coercivity of the second free layer is greater than temperature dependence of coercivity of the first free layer.

Abstract: A perpendicular spin transfer torque MRAM memory cell includes a magnetic tunnel junction that has a free layer, a pinned layer and a tunnel barrier between the free layer and the pinned layer. The free layer has a switchable direction of magnetization perpendicular to the plane of the free layer. A cap layer is provided adjacent to the magnetic tunnel junction. The thickness of the cap layer is increased so that the cap layer acts as a heating layer, which results in a reduction of the current density during writing and increases the write margin. In some embodiments, a resistive heating layer is added to the memory cell, adjacent to the cap layer, in order to achieve the lower current density and increased write margin while also improving signal to noise ration during reading by eliminating shot noise.

Abstract: A perpendicular spin orbit torque MRAM memory cell comprises a magnetic tunnel junction that includes a free layer in a plane, a ferromagnetic layer and a spacer layer between the ferromagnetic layer and the free layer. The free layer comprises a switchable direction of magnetization perpendicular to the plane. The ferromagnetic layer is configured to generate perpendicularly polarized spin current in response to an electrical current through the ferromagnetic layer and inject the perpendicularly polarized spin current through the spacer layer into the free layer to change the direction of magnetization of the free layer.

Abstract: An apparatus comprises a main pole, a trailing shield, a write-field-enhancing structure, a write coil, a write current control circuit configured to supply a write current to the write coil to record a bit to a magnetic medium, and a driving current control circuit configured to supply a driving current to the write-field-enhancing structure, wherein the driving current comprises a driving pulse, and wherein the driving current comprises an AC component with a duty cycle selected based at least in part on a power constraint. A method of writing to a magnetic medium comprises supplying a write current to a write coil of a magnetic write head, and supplying a driving current to a free layer disposed in a write gap between a main pole and a trailing shield, wherein the driving current comprises an AC component with a duty cycle based at least in part on a power constraint.

Abstract: A perpendicular spin orbit torque MRAM memory cell comprises a magnetic tunnel junction that includes a free layer in a plane, a ferromagnetic layer and a spacer layer between the ferromagnetic layer and the free layer. The free layer comprises a switchable direction of magnetization perpendicular to the plane. The ferromagnetic layer is configured to generate perpendicularly polarized spin current in response to an electrical current through the ferromagnetic layer and inject the perpendicularly polarized spin current through the spacer layer into the free layer to change the direction of magnetization of the free layer.

Abstract: An apparatus comprises a main pole, a trailing shield, a write-field-enhancing structure, a write coil, a write current control circuit configured to supply a write current to the write coil to record a bit to a magnetic medium, and a driving current control circuit configured to supply a driving current to the write-field-enhancing structure, wherein the driving current comprises a driving pulse, and wherein the driving current comprises an AC component with a duty cycle selected based at least in part on a power constraint. A method of writing to a magnetic medium comprises supplying a write current to a write coil of a magnetic write head, and supplying a driving current to a free layer disposed in a write gap between a main pole and a trailing shield, wherein the driving current comprises an AC component with a duty cycle based at least in part on a power constraint.

Abstract: Disclosed herein are apparatuses and methods for writing to a magnetic medium, and data storage devices comprising such apparatuses and methods. An apparatus comprises a main pole, a trailing shield, a write-field-enhancing structure, a write coil, a write current control circuit configured to supply a write current to the write coil to record a bit to a magnetic medium, and a driving current control circuit configured to supply a driving current to the write-field-enhancing structure, wherein the driving current comprises a driving pulse. A method of writing to a magnetic medium comprises supplying a write current to a write coil of a magnetic write head, and supplying a driving current to a free layer disposed in a write gap between a main pole and a trailing shield of the magnetic write head, wherein the driving current comprises an AC component.

Abstract: The present disclosure generally relates to a SOT-MRAM cell that has a spin Hall effect layer and a magnetic tunnel junction. The magnetic tunnel junction is disposed at an edge of the spin Hall effect layer. In order to write the cell, current is applied through the spin Hall effect layer to create spin accumulation of z-polarized spins under the free layer due to the spin Hall effect. The spins exert a spin torque on the free layer via spin diffusion. Based upon the design, the SOT-MRAM cell has deterministic switching of the perpendicular free layer with the spin Hall effect layer without application of an external magnetic field.

Abstract: A method and apparatus for deterministically switching a free layer in a spin orbit torque magnetoresistive random access memory (SOT-MRAM) cell is disclosed herein. In one embodiment, an SOT-MRAM memory cell is provided. The SOT-MRAM memory cell includes a magnetic tunnel junction, a ferromagnetic bias layer, and an antiferromagnetic layer. The magnetic tunnel junction includes a free layer having primarily two bi-stable magnetization directions, a reference layer having a fixed magnetization direction, and an insulating tunnel barrier layer positioned between the free layer and the reference layer. The ferromagnetic bias layer is configured to provide spin orbit torque via anomalous Hall effect and simultaneously configured to provide a magnetic bias field on the free layer to achieve deterministic switching. The antiferromagnetic layer is positioned below the ferromagnetic bias layer and is configured to pin a magnetization direction of the ferromagnetic bias layer in a predetermined direction.