Abstract: Methods of forming semiconductor-superconductor hybrid devices with a horizontally-confined channel are described. An example method includes forming a first isolated semiconductor heterostructure and a second isolated semiconductor heterostructure. The method further includes forming a left gate adjacent to a first side of each of the first isolated semiconductor heterostructure and the second isolated semiconductor heterostructure. The method further includes forming a right gate adjacent to a second side, opposite to the first side, of each of the first isolated semiconductor heterostructure and the second isolated semiconductor heterostructure, where a top surface of each of the left gate and the right gate is offset vertically from a selected surface of each of the first isolated semiconductor heterostructure and the second isolated semiconductor heterostructure by a predetermined offset amount.

Abstract: Methods of forming semiconductor-superconductor hybrid devices with a horizontally-confined channel are described. An example method includes forming a first isolated semiconductor heterostructure and a second isolated semiconductor heterostructure. The method further includes forming a left gate adjacent to a first side of each of the first isolated semiconductor heterostructure and the second isolated semiconductor heterostructure. The method further includes forming a right gate adjacent to a second side, opposite to the first side, of each of the first isolated semiconductor heterostructure and the second isolated semiconductor heterostructure, where a top surface of each of the left gate and the right gate is offset vertically from a selected surface of each of the first isolated semiconductor heterostructure and the second isolated semiconductor heterostructure by a predetermined offset amount.

Abstract: A device comprising: a portion of semiconductor; a portion of superconductor arranged to a enable a topological phase having a topological gap to be induced in a region of the semiconductor by proximity effect; and a portion of a non-magnetic material comprising an element with atomic number Z greater than or equal to 26, arranged to increase the topological gap in the topological region of the semiconductor.

Abstract: A semiconductor-superconductor hybrid device comprises a semiconductor, a superconductor, and a barrier between the superconductor and the semiconductor. The device is configured to enable energy level hybridisation between the semiconductor and the superconductor. The barrier is configured to increase a topological gap of the device. The barrier allows for control over the degree of hybridisation between the semiconductor and the superconductor. Further aspects provide a quantum computer comprising the device, a method of manufacturing the device, and a method of inducing topological behaviour in the device.

Abstract: A method of fabricating a device, wherein the device comprises a plurality of lengths of material and at least one junction joining two or more of the lengths of material. In a masking phase, a mask is formed on an underlying layer of the device. The mask comprises a plurality of trenches exposing the underlying layer, each trench corresponding to one of the lengths of material. A respective section of two or more of the trenches either (a) narrow down, or (b) are separated by a discontinuity, at a position corresponding to the at least one junction. In a selective area growth phase, material is grown in the set of trenches to form the lengths of material on the underlying layer. The two or more lengths of material are joined at the at least one junction.

Abstract: A device comprising: a portion of semiconductor; a portion of superconductor arranged to a enable a topological phase having a topological gap to be induced in a region of the semiconductor by proximity effect; and a portion of a non-magnetic material comprising an element with atomic number Z greater than or equal to 26, arranged to increase the topological gap in the topological region of the semiconductor.

Abstract: A method of fabricating a device, wherein the device comprises a plurality of lengths of material and at least one junction joining two or more of the lengths of material. In a masking phase, a mask is formed on an underlying layer of the device. The mask comprises a plurality of trenches exposing the underlying layer, each trench corresponding to one of the lengths of material. A respective section of two or more of the trenches either (a) narrow down, or (b) are separated by a discontinuity, at a position corresponding to the at least one junction. In a selective area growth phase, material is grown in the set of trenches to form the lengths of material on the underlying layer. The two or more lengths of material are joined at the at least one junction.