A spin current magnetization rotational element according to the present disclosure includes a first ferromagnetic metal layer configured for a direction of magnetization to be changed and a spin-orbit torque wiring extending in a direction intersecting a lamination direction of the first ferromagnetic metal layer and bonded to the first ferromagnetic metal layer. The spin-orbit torque wiring includes a narrow portion, and at least a part of the narrow portion constitutes a junction to the first ferromagnetic metal layer.

A frequency sensor is provided. The frequency sensor may include: a magnetoresistive nano-oscillator including a magnetic heterostructure of at least a magnetic free layer, a magnetic reference layer and a non-magnetic intermediate layer arranged between the magnetic free layer and the magnetic reference layer; a coupling arrangement for coupling an incoming signal to at least one magnetic mode of the magnetic free layer, and a frequency estimator. The frequency estimator may be configured to: perform a plurality of voltage measurements across the magnetoresistive nano-oscillator over time; calculate a time averaged voltage across the magnetoresistive nano-oscillator based on the plurality of voltage measurements; estimate, over a finite range of frequencies, a frequency of the incoming signal based on the calculated time averaged voltage, and output a signal representative of the estimated frequency. A method of estimating a frequency of an incoming signal is also provided.

A memory device includes a plurality of layers forming a stack. The plurality of layers include a spin polarization layer having a magnetic anisotropy approximately perpendicular to a plane of the spin polarization layer, an antiferromagnetic layer having an antiferromagnetic material, a ferromagnetic layer that is exchange coupled to the antiferromagnetic layer, where the antiferromagnetic layer is between the ferromagnetic layer and the spin polarization layer, and a storage layer having a magnetization direction that indicates a memory state of the storage layer. The memory state is switched by an amount of current through the stack. The spin polarization layer, the ferromagnetic layer, and the antiferromagnetic layer are configured to reduce the amount of current through the stack for switching the magnetization direction of the storage layer relative to an amount of current through a memory device without the spin polarization layer, the ferromagnetic layer, and the antiferromagnetic layer.

A resonator, an oscillator, and a quantum computer in which the area occupied by the circuit can be reduced is provided. A resonator (100) includes a loop circuit (110) in which a first superconducting line (101), a first Josephson junction (103), a second superconducting line (102), and a second Josephson junction (104) are connected in a ring shape, and a capacitor (120). The capacitor (120) and the loop circuit (110) are connected in a ring shape.

A spin torque oscillator includes a first electrode, a second electrode and a device layer stack located between the first electrode and the second electrode. The device layer stack includes a spin polarization layer including a first ferromagnetic material, an assist layer including a third ferromagnetic material, a ferromagnetic oscillation layer including a second ferromagnetic material located between the spin polarization layer and the assist layer, a nonmagnetic spacer layer located between the spin polarization layer and the ferromagnetic oscillation, and a nonmagnetic coupling layer located between the ferromagnetic oscillation layer and the assist layer. The assist layer is antiferromagnetically coupled to the ferromagnetic oscillation layer through the non-magnetic coupling layer, and the assist layer has a magnetization that is coupled to a magnetization of the ferromagnetic oscillation layer.

A superconducting input and/or output system employs at least one microwave superconducting resonator. The microwave superconducting resonator(s) may be communicatively coupled to a microwave transmission line. Each microwave superconducting resonator may include a first and a second DC SQUID, in series with one another and with an inductance (e.g., inductor), and a capacitance in parallel with the first and second DC SQUIDs and inductance. Respective inductive interfaces are operable to apply flux bias to control the DC SQUIDs. The second DC SQUID may be coupled to a Quantum Flux Parametron (QFP), for example as a final element in a shift register. A superconducting parallel plate capacitor structure and method of fabricating such are also taught.

This spin current magnetization rotational type magnetoresistive element includes a magnetoresistive effect element having a first ferromagnetic metal layer having a fixed magnetization orientation, a second ferromagnetic metal layer having a variable magnetization orientation, and a non-magnetic layer sandwiched between the first ferromagnetic metal layer and the second ferromagnetic metal layer, and spin-orbit torque wiring which extends in a direction that intersects the stacking direction of the magnetoresistive effect element, and is connected to the second ferromagnetic metal layer, wherein the electric current that flows through the magnetoresistive effect element and the electric current that flows through the spin-orbit torque wiring merge or are distributed in the portion where the magnetoresistive effect element and the spin-orbit torque wiring are connected.

This spin current magnetization rotational type magnetoresistive element includes a magnetoresistive effect element having a first ferromagnetic metal layer having a fixed magnetization orientation, a second ferromagnetic metal layer having a variable magnetization orientation, and a non-magnetic layer sandwiched between the first ferromagnetic metal layer and the second ferromagnetic metal layer, and spin-orbit torque wiring which extends in a direction that intersects the stacking direction of the magnetoresistive effect element, and is connected to the second ferromagnetic metal layer, wherein the electric current that flows through the magnetoresistive effect element and the electric current that flows through the spin-orbit torque wiring merge or are distributed in the portion where the magnetoresistive effect element and the spin-orbit torque wiring are connected.

In example embodiments, an RF-to-DC converter includes one or more unit cells that integrate a spintronic element (e.g., a magnetic tunnel junction (MTJ)) into a conductor ring RF energy absorber (e.g., a split-ring resonator (SRR)). A RF-to-DC converter that includes one or more MTJ-integrated SRR unit cells may provide compactness, as each unit cell includes its own independent SRR and integrated MTJ; scalability, as multiple unit cells may be connected into an array to increase DC power output; and energy harvesting efficiency, as a MTJ may be much more sensitive than a Schottky diode and the SRR of each unit cell may directly feed energy to a MTJ without impedance matching circuits.

A magnetic device for magnetic random access memory (MRAM), spin torque MRAM, or spin torque oscillator technology is disclosed wherein a magnetic tunnel junction (MTJ) with a sidewall is formed between a bottom electrode and a top electrode. A passivation layer that is a single layer or multilayer comprising one of B, C, or Ge, or an alloy thereof wherein the B, C, and Ge content, respectively, is at least 10 atomic % is formed on the MTJ sidewall to protect the MTJ from reactive species during subsequent processing including deposition of a dielectric layer that electrically isolates the MTJ from adjacent MTJs, and during annealing steps around 400° C. in CMOS fabrication. The single layer is about 3 to 10 Angstroms thick and may be an oxide or nitride of B, C, or Ge. The passivation layer is preferably amorphous to prevent diffusion of reactive oxygen or nitrogen species.