In various embodiments, superconducting wires incorporate diffusion barriers composed of Nb alloys or NbTa alloys that resist internal diffusion and provide superior mechanical strength to the wires.

A technique relates a superconducting microwave cavity. An array of posts has different heights in the cavity, and the array supports a localized microwave mode. The array of posts includes lower resonant frequency posts and higher resonant frequency posts. The higher resonant frequency posts are arranged around the lower resonant frequency posts. A first plate is opposite a second plate in the cavity. One end of the lower resonant frequency posts is positioned on the second plate so as to be electrically connected to the second plate. Another end of the lower resonant frequency posts in the array is open so as not to form an electrical connection to the first plate. Qubits are connected to the lower resonant frequency posts in the array of posts, such that each of the qubits is physically connected to one or two of the lower resonant frequency posts in the array of posts.

A stacked quantum computing device including a first chip that includes a first dielectric substrate and a superconducting qubit on the first dielectric substrate, and a second chip that is bonded to the first chip and includes a second dielectric substrate, a qubit readout element on the second dielectric substrate, a control wire on the second dielectric substrate, a dielectric layer covering the control wire, and a shielding layer covering the dielectric layer.

A technique relates a superconducting microwave cavity. An array of posts has different heights in the cavity, and the array supports a localized microwave mode. The array of posts includes lower resonant frequency posts and higher resonant frequency posts. The higher resonant frequency posts are arranged around the lower resonant frequency posts. A first plate is opposite a second plate in the cavity. One end of the lower resonant frequency posts is positioned on the second plate so as to be electrically connected to the second plate. Another end of the lower resonant frequency posts in the array is open so as not to form an electrical connection to the first plate. Qubits are connected to the lower resonant frequency posts in the array of posts, such that each of the qubits is physically connected to one or two of the lower resonant frequency posts in the array of posts.

A superconducting material includes YBa.sub.2Cu.sub.3O.sub.7-? and a nano-structured, preferably nanowires, WO.sub.3 dopant in a range of from 0.01 to 3.0 wt. %, preferably 0.075 to 0.2 wt. %, based on total material weight. Methods of making the superconductor may preferably avoid solvents and pursue solid-state synthesis employing Y, Ba, and/or Cu oxides and/or carbonates.

The present invention relates to a quantum computing unit comprising a superconducting substrate or other superconducting component, at least three outer Majorana modes, and at least one inner Majorana mode, wherein the at least three outer Majorana modes are located along an outer perimeter, and wherein the at least one inner Majorana mode is located within the outer perimeter. This spatial configuration of the four participating Majorana modes allows to control the time-dependent coupling between the respective Majorana modes. The related quantum gates can be performed perfectly in a finite time, preferably with a frequency of up to several GHz. These include the braiding gate, the ?/8 magic phase gate, the ?/12 phase gate, and, for multi-qubit systems, the CNOT gate. The robustness of the mechanism guarantees that for special times the quantum gate is conducted the quantum gate is perfectly realized. This property is independent of material specific parameters. Hence, the behavior can be expected in all systems where Majorana zero modes appear in the center of Abrikosov vortices, in particular, not only in FeTeSe, which we consider as an example.

The present invention relates to a quantum computing unit comprising a superconducting substrate or other superconducting component, at least three outer Majorana modes, and at least one inner Majorana mode, wherein the at least three outer Majorana modes are located along an outer perimeter, and wherein the at least one inner Majorana mode is located within the outer perimeter. This spatial configuration of the four participating Majorana modes allows to control the time-dependent coupling between the respective Majorana modes. The related quantum gates can be performed perfectly in a finite time, preferably with a frequency of up to several GHz. These include the braiding gate, the ?/8 magic phase gate, the ?/12 phase gate, and, for multi-qubit systems, the CNOT gate. The robustness of the mechanism guarantees that for special times the quantum gate is conducted the quantum gate is perfectly realized. This property is independent of material specific parameters. Hence, the behavior can be expected in all systems where Majorana zero modes appear in the center of Abrikosov vortices, in particular, not only in FeTeSe, which we consider as an example.

An ultra-thin film superconducting tape and method for fabricating same is disclosed. Embodiments are directed to a superconducting tape being fabricated by processes which include removing a portion of the superconducting tape's substrate subsequent the substrate's initial formation, whereby a thickness of the superconducting tape is reduced to 15-80 m.

The present disclosure relates to a superconductor including magnesium diboride and a production method therefor. A superconductor having a high critical current density at a certain temperature and under a certain magnetic field may be obtained by doping magnesium diboride with liquid chloroform during the production of the superconductor.

The present disclosure relates to a superconductor including magnesium diboride and a production method therefor. A superconductor having a high critical current density at a certain temperature and under a certain magnetic field may be obtained by doping magnesium diboride with liquid chloroform during the production of the superconductor.