A magnetoresistive effect oscillator executes a first step of applying a current, which has a first current density larger than a critical current density J.sub.O for oscillation, to a magnetoresistive effect element for a time T.sub.P, and then executes a second step of applying a current, which has a second current density J.sub.S smaller than the first current density and not smaller than the critical current density J.sub.O for oscillation, to the magnetoresistive effect element. The following formulae (1), (2) and (3), or the following formulae (1) and (4) are satisfied on an assumption that an average value of the first current density during the time T.sub.P in the first step is J.sub.P, a critical current density for magnetization reversal of the magnetoresistive effect element is J.sub.R, and a magnetization reversal time of the magnetoresistive effect element is T.sub.R: $\begin{array}{cc}\frac{0.1\times T_R\left(J_R-J_O\right)}{J_p-J_S}<T_p<0.9\times T_R\frac{J_R-J_O}{J_S-J_O}& \end{array}$

An oscillator in which crosstalk can be reduced is provided. An oscillator includes a SQUID, a transmission line connected to the SQUID, a ground plane, and a first connection circuit disposed in a vicinity of a node of an electric field of a standing wave that is generated when the oscillator is oscillating, the first connection circuit connecting parts of the ground plane located on both sides of the transmission line to each other.

A reservoir computer. In some embodiments, the reservoir computer includes a Duffing oscillator, and a readout circuit, and the readout circuit is configured to calculate a plurality of products, each of the products being calculated by multiplying a sample, of a plurality of samples of a signal from the Duffing oscillator, by a respective weight of a plurality of weights.

A SOT device includes a bismuth antimony dopant element (BiSbE) alloy layer over a substrate. The BiSbE alloy layer is used as a topological insulator. The BiSbE alloy layer includes bismuth, antimony, AND a dopant element. The dopant element is a non-metallic dopant element, a metallic dopant element, and combinations thereof. Examples of metallic dopant elements include Ni, Co, Fe, CoFe, NiFe, NiCo, NiCu, CoCu, NiAg, CuAg, Cu, Al, Zn, Ag, Ga, In, or combinations thereof. Examples of non-metallic dopant elements include Si, P, Ge, or combinations thereof. The BiSbE alloy layer can include a plurality of BiSb lamellae layers and one or more dopant element lamellae layers. The BiSbE alloy layer has a (012) orientation.

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 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.

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.

Disclosed herein is a detection device comprising sensors with spin torque oscillators (STOs), at least one fluidic channel configured to receive molecules to be detected, and detection circuitry coupled to the sensors. At least some of the molecules to be detected are labeled by magnetic nanoparticles (MNPs). The presence of one or more MNPs in the vicinity of a STO subjected to a bias current changes the oscillation frequency of the STO. The sensors are encapsulated by a material, such as an insulator, separating the sensors from the at least one fluidic channel. A surface of the material provides binding sites for the molecules to be detected. The detection circuitry is configured to detect changes in the oscillation frequencies of the sensors in response to presence or absence of one or more MNPs coupled to one or more binding sites associated with the sensors.

Disclosed is a method for generating, from a first electric current having a first frequency, a plurality of second currents each having a second respective frequency component, the method including the following steps: supplying a frequency distributor including a first set of pillars including a layer made from a first magnetic material and having a resonance frequency; exciting each pillar of the first set with an electromagnetic field having the first frequency, the ratio between twice the resonance frequency of each pillar of the first set and the first frequency being equal, to within ten percent, to a first natural integer; and generating, by each pillar of the first set, a second frequency component in the second respective current.