A magnetoresistance effect element includes a first ferromagnetic layer, a second ferromagnetic layer, and a nonmagnetic spacer layer between the first ferromagnetic layer and the second ferromagnetic layer, in which at least one of the first ferromagnetic layer and the second ferromagnetic layer contains a metal compound having a half-Heusler type crystal structure, the metal compound contains a functional material, and X atoms, Y atoms, and Z atoms which form a unit lattice of the half-Heusler type crystal structure, and the functional material has an atomic number lower than an atomic number of any of the X atoms, the Y atoms, and the Z atoms.

A magnetic structure includes a magnetic tunnel junction based on a synthetic antiferromagnetic free layer which is regulated by an electric field, and a spin-orbit layer located below the magnetic tunnel junction. The transformation from the antiferromagnetic coupling to the ferromagnetic coupling of the free layer based on a synthetic antiferromagnetic multilayer structure is controlled by an electric field. A spin-orbit torque magnetic random access memory, which includes the magnetic structure, is able to realize stable data writing under the combined interaction of electric field and current, and has advantages of simple structure for scaling, ultralow power consumption, ultrahigh speed of switching, radiation resistance and non-volatility.

A device is disclosed. The device includes a tetragonal Heusler compound of the form Mn.sub.3-xCo.sub.xGe, wherein 0<x1, wherein Co accounts for at least 0.4 atomic percent of the Heusler compound. The device also includes a substrate oriented in the direction (001) and of the form YMn.sub.1+d, wherein Y includes an element selected from the group consisting of Ir and Pt, and 0d4. The tetragonal Heusler compound and the substrate are in proximity with each other, thereby allowing spin-polarized current to pass from one through the other. In one aspect, the device also includes a multi-layered structure that is non-magnetic at room temperature. The structure includes alternating layers of Co and E. E includes at least one other element that includes Al. The composition of the structure is represented by Co.sub.1-yE.sub.y, with y being in the range from 0.45 to 0.55.

A magnetoresistance effect element has a first ferromagnetic metal layer, a second ferromagnetic metal layer, and a tunnel barrier layer that is sandwiched between the first and second ferromagnetic metal layers, and the tunnel barrier layer has a spinel structure represented by a composition formula AGa.sub.2O.sub.x (0<x4), and an A-site is a non-magnetic divalent cation which is one or more selected from a group consisting of magnesium, zinc and cadmium.

An apparatus for generation of coherent terahertz radiation is provided. In one example, the apparatus includes one or more multilayer tunable microcolumns. In turn, a multilayer tunable microcolumn can include a substrate, a bottom electrode, a bottom layer of a ferromagnetic material further comprising a magnon gain medium (MGM) coupled to the bottom electrode, a tunnel junction coupled to the ferromagnetic material, a spin injector coupled to the tunnel junction, a pinning layer coupled to the spin injector, a reference layer coupled to the pinning layer and a top electrode. In one example, a containment cavity encloses at least one of the multilayer tunable microcolumns. In one example, a storage cavity encloses the containment cavity.

A magnetoresistance effect element has a first ferromagnetic metal layer, a second ferromagnetic metal layer, and a tunnel barrier layer that is sandwiched between the first and second ferromagnetic metal layers, the tunnel barrier layer is expressed by a chemical formula of AB.sub.2O.sub.x, and has a spinel structure in which cations are arranged in a disordered manner, A represents a divalent cation that is either Mg or Zn, and B represents a trivalent cation that includes a plurality of elements selected from the group consisting of Al, Ga, and In.

A magnetic memory device includes a buffer layer on a substrate, a magnetic tunnel junction structure including a fixed layer structure, a tunnel barrier, and a free layer that are sequentially arranged on the buffer layer, and a spin-orbit torque (SOT) structure on the magnetic tunnel junction structure and including a topological insulator material, wherein the free layer includes a Heusler material.

A magnetic device may include a layer stack. The layer stack may include a first ferromagnetic layer; a non-magnetic spacer layer on the first ferromagnetic layer, where the non-magnetic spacer layer comprises at least one of Ru, Ir, Ta, Cr, W, Mo, Re, Hf, Zr, or V; a second ferromagnetic layer on the non-magnetic spacer layer; and an oxide layer on the second ferromagnetic layer. The magnetic device also may include a voltage source configured to apply a bias voltage across the layer stack to cause switching of a magnetic orientation of the second ferromagnetic layer without application of an external magnetic field or a current. A thickness and composition of the non-magnetic spacer layer may be selected to enable a switching direction of the magnetic orientation of the second ferromagnetic layer to be controlled by a sign of the bias voltage.

There is provided a magnetoresistive effect element having improved magnetoresistive effect. A magnetoresistive effect element MR includes a first ferromagnetic layer 4 as a fixed magnetization layer, a second ferromagnetic layer 6 as a free magnetization layer, and a nonmagnetic spacer layer 5 provided between the first ferromagnetic layer 4 and the second ferromagnetic layer 6. The nonmagnetic spacer layer 5 includes at least one of a first insertion layer 5A provided under the nonmagnetic spacer layer 5 and a second insertion layer 5C provided over the nonmagnetic spacer layer 5. The first insertion layer 5A and the second insertion layer 5C are made of Fe.sub.2TiSi.

A device and method for providing the device are described. The device includes a substrate, a Mn.sub.xN layer overlying the substrate, a multi-layered structure that is non-magnetic at room temperature and a first magnetic layer. The Mn.sub.xN layer has 2x4.75. The multi-layered structure comprises alternating layers of Co and E, wherein E comprises at least one other element that includes Al. The composition of the multi-layered structure is represented by Co.sub.1-xE.sub.x, with x being in the range from 0.45 to 0.55. The first magnetic layer includes a Heusler compound. The first magnetic layer is in contact with the multi-layered structure and the first magnetic layer forms part of a magnetic tunnel junction.