A controllable magnetic connection element comprising a dilute magnetic semiconductor for connecting topological qubits includes a magnetic connector and a magnet. The magnet is configured to alter a paramagnetic/diamagnetic character of the magnetic connector to control the magnetic connection to allow or prevent the transmission of a spin current between the topological qubits. A method for controlling entanglement between topological qubits includes controlling a magnetic field around a magnetic connection between the topological qubits to interrupt or allow transmission of spin polarised electrons between the topological qubits and thereby entangle or prevent entanglement between them.

A controllable magnetic connection element comprising a dilute magnetic semiconductor for connecting topological qubits includes a magnetic connector and a magnet. The magnet is configured to alter a paramagnetic/diamagnetic character of the magnetic connector to control the magnetic connection to allow or prevent the transmission of a spin current between the topological qubits. A method for controlling entanglement between topological qubits includes controlling a magnetic field around a magnetic connection between the topological qubits to interrupt or allow transmission of spin polarised electrons between the topological qubits and thereby entangle or prevent entanglement between them.

A superconducting device includes a frequency tunable device comprising a first conductive pad and a second conductive pad that are connected to each other by a Josephson junction, a ferromagnetic structure disposed at a predetermined distance apart from the first and second conductive pads, a control line located below the ferromagnetic structure, and a control circuit configured to control a resonant frequency of the frequency tunable device by controlling current flowing through the control line.

A superconducting device includes a frequency tunable device comprising a first conductive pad and a second conductive pad that are connected to each other by a Josephson junction, a ferromagnetic structure disposed at a predetermined distance apart from the first and second conductive pads, a control line located below the ferromagnetic structure, and a control circuit configured to control a resonant frequency of the frequency tunable device by controlling current flowing through the control line.

This disclosure includes a method for fabricating an air bridge, an air bridge structure, and a superconducting quantum chip, and relates to the field of circuit structures. In some examples, a method for fabricating an air bridge includes forming an air bridge brace structure on a substrate, and forming, on the air bridge brace structure and the substrate, an air bridge material layer with one or more openings in the air bridge material layer that reveal the air bridge brace structure. The air bridge material layer with the one or more openings is formed based on a patterned photoresist layer with patterns corresponding to the one or more openings. The method further includes removing, based on the one or more openings in the air bridge material layer, the air bridge brace structure to obtain the air bridge having the one or more openings.

This disclosure includes a method for fabricating an air bridge, an air bridge structure, and a superconducting quantum chip, and relates to the field of circuit structures. In some examples, a method for fabricating an air bridge includes forming an air bridge brace structure on a substrate, and forming, on the air bridge brace structure and the substrate, an air bridge material layer with one or more openings in the air bridge material layer that reveal the air bridge brace structure. The air bridge material layer with the one or more openings is formed based on a patterned photoresist layer with patterns corresponding to the one or more openings. The method further includes removing, based on the one or more openings in the air bridge material layer, the air bridge brace structure to obtain the air bridge having the one or more openings.

A strip conductor device includes first and second elongated strip conductor elements, each configured to be coupled at a coupling-in end to a contact device for coupling-in electric current and at a coupling-out end to a contact device for coupling-out electric current. The first elongated strip conductor element is a first strip conductor that has a substrate layer that carries a conductor layer that has barrier elements along a length of the conductor layer. The second elongated strip conductor element is a second strip conductor that has a substrate layer that carries a conductor layer that has barrier elements along a length of the conductor layer. The first strip conductor element forms a layer arrangement with the second strip conductor element and the coupling-in ends and the coupling-out ends of the first and second strip conductor elements lie one above the other.

A strip conductor device includes first and second elongated strip conductor elements, each configured to be coupled at a coupling-in end to a contact device for coupling-in electric current and at a coupling-out end to a contact device for coupling-out electric current. The first elongated strip conductor element is a first strip conductor that has a substrate layer that carries a conductor layer that has barrier elements along a length of the conductor layer. The second elongated strip conductor element is a second strip conductor that has a substrate layer that carries a conductor layer that has barrier elements along a length of the conductor layer. The first strip conductor element forms a layer arrangement with the second strip conductor element and the coupling-in ends and the coupling-out ends of the first and second strip conductor elements lie one above the other.

In a method for fabricating an air bridge, an air bridge brace structure is formed on a substrate. A continuous air bridge material layer is formed over the air bridge brace structure and the substrate. One or more openings are formed in the continuous air bridge material layer to reveal portions of the air bridge brace structure. A bridge brace material of the air bridge brace structure is removed through the one or more openings to obtain the air bridge. The air bridge includes the substrate and an air bridge structure that is disposed on the substrate. The air bridge structure includes the one or more openings. The one or more openings includes a first opening configured to pass through an etchant used to remove the bridge brace material. The one or more openings includes a second opening configured to pass through the bridge brace material removed by the etchant.

In a method for fabricating an air bridge, an air bridge brace structure is formed on a substrate. A continuous air bridge material layer is formed over the air bridge brace structure and the substrate. One or more openings are formed in the continuous air bridge material layer to reveal portions of the air bridge brace structure. A bridge brace material of the air bridge brace structure is removed through the one or more openings to obtain the air bridge. The air bridge includes the substrate and an air bridge structure that is disposed on the substrate. The air bridge structure includes the one or more openings. The one or more openings includes a first opening configured to pass through an etchant used to remove the bridge brace material. The one or more openings includes a second opening configured to pass through the bridge brace material removed by the etchant.