Abstract: A high-temperature superconducting film includes a SrTiO3 substrate, a single crystalline FeSe layer, and a protective layer with a layered crystal structure. The single crystalline FeSe layer is sandwiched between the SrTiO3 substrate and the protective layer via a layer-by-layer mode. An onset temperature of superconducting transition of the high-temperature superconducting film is greater than or equal to 54 K, and a critical current density of the high-temperature superconducting film is about 106 A/cm2 at 12 K.

Abstract: A method for making a high-temperature superconducting film includes loading a SrTiO3 substrate in an ultra-high vacuum system. A single crystalline FeSe layer is grown on a surface of the SrTiO3 substrate by molecular beam epitaxy. A protective layer with a layered crystal structure is grown by molecular beam epitaxy and covering the single crystalline FeSe layer.

Abstract: A method for forming a topological insulator structure is provided. A strontium titanate substrate having a surface (111) is used. The surface (111) of the strontium titanate substrate is cleaned by heat-treating the strontium titanate substrate in the molecular beam epitaxy chamber. The strontium titanate substrate is heated and Bi beam, Sb beam, Cr beam, and Te beam are formed in the molecular beam epitaxy chamber in a controlled ratio achieved by controlling flow rates of the Bi beam, Sb beam, Cr beam, and Te beam. The magnetically doped topological insulator quantum well film is formed on the surface (111) of the strontium titanate substrate. The amount of the hole type charge carriers introduced by the doping with Cr is substantially equal to the amount of the electron type charge carriers introduced by the doping with Bi.

Abstract: A method for generating quantum anomalous Hall effect is provided. A topological insulator quantum well film in 3QL to 5QL is formed on an insulating substrate. The topological insulator quantum well film is doped with a first element and a second element to form the magnetically doped topological insulator quantum well film. The doping of the first element and the second element respectively introduce hole type charge carriers and electron type charge carriers in the magnetically doped topological insulator quantum well film, to decrease the carrier density of the magnetically doped topological insulator quantum well film to be smaller than or equal to 1×1013 cm?2. One of the first element and the second element magnetically dopes the topological insulator quantum well film. An electric field is applied to the magnetically doped topological insulator quantum well film to decrease the carrier density.

Abstract: A method for making a high-temperature superconducting film includes loading a SrTiO3 substrate in an ultra-high vacuum system. A single crystalline FeSe layer is grown on a surface of the SrTiO3 substrate by molecular beam epitaxy. A protective layer with a layered crystal structure is grown by molecular beam epitaxy and covering the single crystalline FeSe layer.

Abstract: A high-temperature superconducting film includes a SrTiO3 substrate, a single crystalline FeSe layer, and a protective layer with a layered crystal structure. The single crystalline FeSe layer is sandwiched between the SrTiO3 substrate and the protective layer via a layer-by-layer mode. An onset temperature of superconducting transition of the high-temperature superconducting film is greater than or equal to 54 K, and a critical current density of the high-temperature superconducting film is about 106 A/cm2 at 12 K.

Abstract: An electrical device includes an insulating substrate and a magnetically doped TI quantum well film. The insulating substrate includes a first surface and a second surface. The magnetically doped topological insulator quantum well film is located on the first surface of the insulating substrate. A material of the magnetically doped topological insulator quantum well film is represented by a chemical formula of Cry(BixSb1-x)2-yTe3, wherein 0<x<1, 0<y<2, and values of x and y satisfies that an amount of a hole type charge carriers introduced by a doping with Cr is substantially equal to an amount of an electron type charge carriers introduced by a doping with Bi, the magnetically doped topological insulator quantum well film is in 3 QL thickness to 5 QL thickness.

Abstract: A topological insulator structure includes an insulating substrate and a magnetically doped TI quantum well film located on the insulating substrate. A material of the magnetically doped TI quantum well film is represented by a chemical formula of Cry(BixSb1-x)2-yTe3. 0.05<x<0.3, 0<y<0.3, and 1:2<x:y<2:1. The magnetically doped TI quantum well film is in 3 QL to 5 QL.

Abstract: A topological insulator structure includes an insulating substrate and a magnetically doped TI quantum well film located on the insulating substrate. A material of the magnetically doped TI quantum well film is represented by a chemical formula of Cry(BixSb1-x)2-yTe3. 0<x<1, 0<y<2. Values of x and y satisfies that an amount of a hole type charge carriers introduced by a doping with Cr is substantially equal to an amount of an electron type charge carriers introduced by a doping with Bi. The magnetically doped TI quantum well film is in 3 QL to 5 QL.

Abstract: A topological insulator structure includes an insulating substrate and a magnetically doped TI quantum well film located on the insulating substrate. A material of the magnetically doped TI quantum well film is represented by a chemical formula of Cry(BixSb1-x)2-yTe3. 0.05<x<0.3, 0<y<0.3, and 1:2<x:y<2:1. The magnetically doped TI quantum well film is in 3 QL to 5 QL.

Abstract: A topological insulator structure includes an insulating substrate and a magnetically doped TI quantum well film located on the insulating substrate. A material of the magnetically doped TI quantum well film is represented by a chemical formula of Cry(BixSb1-x)2-yTe3. 0<x<1, 0<y<2. Values of x and y satisfies that an amount of a hole type charge carriers introduced by a doping with Cr is substantially equal to an amount of an electron type charge carriers introduced by a doping with Bi. The magnetically doped TI quantum well film is in 3 QL to 5 QL.

Abstract: A method for forming a topological insulator structure is provided. A strontium titanate substrate having a surface (111) is used. The surface (111) of the strontium titanate substrate is cleaned by heat-treating the strontium titanate substrate in the molecular beam epitaxy chamber. The strontium titanate substrate is heated and Bi beam, Sb beam, Cr beam, and Te beam are formed in the molecular beam epitaxy chamber in a controlled ratio achieved by controlling flow rates of the Bi beam, Sb beam, Cr beam, and Te beam. The magnetically doped topological insulator quantum well film is formed on the surface (111) of the strontium titanate substrate. The amount of the hole type charge carriers introduced by the doping with Cr is substantially equal to the amount of the electron type charge carriers introduced by the doping with Bi.

Abstract: A method for generating quantum anomalous Hall effect is provided. A topological insulator quantum well film in 3QL to 5QL is formed on an insulating substrate. The topological insulator quantum well film is doped with a first element and a second element to form the magnetically doped topological insulator quantum well film. The doping of the first element and the second element respectively introduce hole type charge carriers and electron type charge carriers in the magnetically doped topological insulator quantum well film, to decrease the carrier density of the magnetically doped topological insulator quantum well film to be smaller than or equal to 1×1013cm?2. One of the first element and the second element magnetically dopes the topological insulator quantum well film. An electric field is applied to the magnetically doped topological insulator quantum well film to decrease the carrier density.

Abstract: An electrical device includes an insulating substrate and a magnetically doped TI quantum well film. The insulating substrate includes a first surface and a second surface. The magnetically doped topological insulator quantum well film is located on the first surface of the insulating substrate. A material of the magnetically doped topological insulator quantum well film is represented by a chemical formula of Cry(BixSb1-x)2-yTe3, wherein 0<x<1, 0<y<2, and values of x and y satisfies that an amount of a hole type charge carriers introduced by a doping with Cr is substantially equal to an amount of an electron type charge carriers introduced by a doping with Bi, the magnetically doped topological insulator quantum well film is in 3 QL thickness to 5 QL thickness.