This semiconductor device comprises an active layer that is formed of an oxide magnetic material and a porous dielectric body that contains water and is provided on the active layer. By using hydrogen and oxygen which are formed by electrolysis of water, the crystal structure of the active layer is changed between a ferromagnetic metal and an antiferromagnetic insulating body.

Provided is a structure having a perpendicular magnetization film which is an (Mn.sub.1-xGa.sub.x).sub.4N.sub.1-y (0<x≦0.5, 0<y<1) thin film having a nitrogen-deficient composition which is formed by controlling and introducing nitrogen N into an MnGa alloy or a thin film containing at least one of Ge, Zn, Sb, Ni, Ag, Sn, Pt, and Rh, instead of Ga. The perpendicular magnetization film exhibits a Curie temperature sufficiently higher than room temperature, has saturation magnetization smaller than that of existing materials, and is capable of being fabricated as a very flat film.

The present disclosure relates to a composition that includes a nanocrystalline core that includes a perovskite and having an outer surface, and a chiral molecule having a functional group, where the functional group is bonded to a first portion of the outer surface, and the composition is capable of circularly polarized luminescence (CPL). In some embodiments of the present disclosure, the composition is capable of absorbing circularly-polarized light.

A method of forming a single phase compositionally complex material including a plurality of transition metals is provided. The method includes creating a magnetic phase diagram to predict magnetic behavior, by calculating expected magnetic states and calculating the spin structure factor by Fourier transform; calculating the spin structure factor by Fourier transform; obtaining a transition temperature from the spin structure factor; selecting the plurality of transition metals and corresponding transition metal composition ratios for the material based on a desired magnetic behavior and the calculated spin structure factor; and forming the material that is a compositionally complex transition metal oxide comprising the plurality of transition metals at the selected composition ratios. The material may be a compositionally complex ABO.sub.3 perovskite film in which A is La and B is the plurality of transition metals including Cr, Mn, Fe, Co, and Ni.

The invention relates to heterostructures including a layer of a two-dimensional material placed on a multiferroic layer. An ordered array of differing polarization domains in the multiferroic layer produces corresponding domains having differing properties in the two-dimensional material. When the multiferroic layer is ferroelectric, the ferroelectric polarization domains in the layer produce local electric fields that penetrate the two-dimensional material. The local electric fields can influence properties of the two-dimensional material, including carrier density, transport properties, optical properties, surface chemistry, piezoelectric-induced strain, magnetic properties, and interlayer spacing. Methods for producing the heterostructures are provided. Devices incorporating the heterostructures are also provided, including tunable sensors, optical emitters, and programmable logic gates.

A first aspect provides a topological quantum computing device comprising a network of semiconductor-superconductor nanowires, each nanowire comprising a length of semiconductor formed over a substrate and a coating of superconductor formed over at least part of the semiconductor; wherein at least some of the nanowires further comprise a coating of ferromagnetic insulator disposed over at least part of the semiconductor. A second aspect provides a method of fabricating a quantum or spintronic device comprising a heterostructure of semiconductor and ferromagnetic insulator, by: forming a portion of the semiconductor over a substrate in a first vacuum chamber, and growing a coating of the ferromagnetic insulator on the semiconductor by epitaxy in a second vacuum chamber connected to the first vacuum chamber by a vacuum tunnel, wherein the semiconductor comprises InAs and the ferromagnetic insulator comprises EuS.

A magnetic material is constituted of a ferromagnetic or ferrimagnetic insulator in a double perovskite structure of Sr.sub.3-xA.sub.xOs.sub.1-yB.sub.yO.sub.6 (0.5≤x≤0.5, −0.5≤y≤0.5). A is an alkali metal or alkaline earth metal atom, and B is a transition metal atom, alkali metal atom, or alkaline earth metal atom). The insulator may be Sr.sub.3OsO.sub.6, where x=y=0 in the above formula. Sr.sub.3OsO.sub.6 is formed to have a cubic crystal structure where strontium atoms, osmium atoms, and oxygen atoms are arranged at lattice points.

The invention relates to heterostructures including a layer of a two-dimensional material placed on a multiferroic layer. An ordered array of differing polarization domains in the multiferroic layer produces corresponding domains having differing properties in the two-dimensional material. When the multiferroic layer is ferroelectric, the ferroelectric polarization domains in the layer produce local electric fields that penetrate the two-dimensional material. The local electric fields can influence properties of the two-dimensional material, including carrier density, transport properties, optical properties, surface chemistry, piezoelectric-induced strain, magnetic properties, and interlayer spacing. Methods for producing the heterostructures are provided. Devices incorporating the heterostructures are also provided, including tunable sensors, optical emitters, and programmable logic gates.

The invention relates to heterostructures including a layer of a two-dimensional material placed on a multiferroic layer. An ordered array of differing polarization domains in the multiferroic layer produces corresponding domains having differing properties in the two-dimensional material. When the multiferroic layer is ferroelectric, the ferroelectric polarization domains in the layer produce local electric fields that penetrate the two-dimensional material. The local electric fields can influence properties of the two-dimensional material, including carrier density, transport properties, optical properties, surface chemistry, piezoelectric-induced strain, magnetic properties, and interlayer spacing. Methods for producing the heterostructures are provided. Devices incorporating the heterostructures are also provided, including tunable sensors, optical emitters, and programmable logic gates.

A first aspect provides a topological quantum computing device comprising a network of semiconductor-superconductor nanowires, each nanowire comprising a length of semiconductor formed over a substrate and a coating of superconductor formed over at least part of the semiconductor; wherein at least some of the nanowires further comprise a coating of ferromagnetic insulator disposed over at least part of the semiconductor. A second aspect provides a method of fabricating a quantum or spintronic device comprising a heterostructure of semiconductor and ferromagnetic insulator, by: forming a portion of the semiconductor over a substrate in a first vacuum chamber, and growing a coating of the ferromagnetic insulator on the semiconductor by epitaxy in a second vacuum chamber connected to the first vacuum chamber by a vacuum tunnel, wherein the semiconductor comprises InAs and the ferromagnetic insulator comprises EuS.