A superconducting material includes YBa.sub.2Cu.sub.3O.sub.7-δ 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.

A superconducting circuit comprises a resonator and a Josephson junction. The resonator comprises an inductor and a capacitor. The inductor comprises a first terminal and a second terminal. The second terminal of the inductor is electrically coupled to a first terminal of the capacitor. A second terminal of the capacitor is electrically coupled to a first terminal of the Josephson junction. The terminal shared by the inductor and the capacitor is configured to be electrically coupled to an alternating current (AC) voltage source having a particular frequency and particular phase. The inductance of the inductor and the capacitance of the capacitor are selected to cause the resonator to resonate at a frequency and a phase that substantially match the particular frequency and the particular phase, respectively, of the AC voltage source to facilitate switching a state of the Josephson junction via a single flux quantum (SFQ) pulse.

An oxide superconducting thin film material includes: a metal substrate having a surface with a biaxially oriented crystal orientation structure; an intermediate layer biaxially oriented and formed on the metal substrate; and an oxide superconducting thin film formed on the intermediate layer and composed of a RE123-based oxide superconductor represented by REBa.sub.2Cu.sub.3O.sub.y. The oxide superconducting thin film includes Br (bromine).

Systems, computer-implemented methods, and techniques facilitating antenna-based thermal annealing of qubits are provided. In one example, a first antenna can be positioned above a superconducting qubit chip having a first Josephson junction and a second Josephson junction. The first antenna can direct a first electromagnetic wave toward the first Josephson junction. A first length of a first defined vertical gap, between the first antenna and the superconducting qubit chip, can be sized to cause the first electromagnetic wave to circumscribe a first set of one or more capacitor pads of the first Josephson junction, thereby annealing the first Josephson junction, without annealing the second Josephson junction. In another example, the first length of the first defined vertical gap can be a function of a model of the first electromagnetic wave as a cone, wherein the cone originates from the first antenna and extends toward the superconducting qubit chip.

Systems and techniques that facilitate spurious junction prevention via in-situ ion milling are provided. In various embodiments, a method can comprise forming a tunnel barrier of a Josephson junction on a substrate during a shadow evaporation process. In various instances, the method can further comprise etching an exposed portion of the tunnel barrier during the shadow evaporation process. In various embodiments, the shadow evaporation process can comprise patterning a resist stack onto the substrate. In various instances, the etching the exposed portion of the tunnel barrier can leave a protected portion of the tunnel barrier within a shadow of the resist stack. In various instances, the shadow of the resist stack can be based on a direction of the etching the exposed portion of the tunnel barrier. In various embodiments, the shadow evaporation process can further comprise depositing a first superconducting material on the substrate after the patterning the resist stack, oxidizing a surface of the first superconducting material to form the tunnel barrier, and depositing a second superconducting material over the protected portion of the tunnel barrier to form a Josephson junction. In various instances, the etching the exposed portion of the tunnel barrier can occur after the oxidizing the surface of the first superconducting material and before the depositing the second superconducting material.

Certain embodiments involve processes or systems for creating various high-temperature superconductive structures or materials. For example, a method can involve depositing a first layer of boron and a second layer of un-doped amorphous carbon on a substrate. The un-doped amorphous carbon is ferromagnetic. The first layer of boron and the second layer of un-doped amorphous carbon are melted by a laser pulse to form a melted boron-doped amorphous carbon. The melted boron-doped amorphous carbon is quenched to create a quenched boron-doped amorphous carbon that is diamagnetic and superconducting. The quenched melted boron-doped amorphous carbon includes a mixture of sp3 bonded carbon atoms and sp2 bonded carbon atoms and a superconducting transition temperature of the quenched boron-doped amorphous carbon is much higher than diamond and increases based on a boron concentration. Undoped Q-carbon is ferromagnetic with Curie temperature above 500K.

Devices, systems, methods, computer-implemented methods, apparatus, and/or computer program products that can facilitate a switch device that shifts frequency of a resonator in a quantum device are provided. According to an embodiment, a device can comprise a readout resonator coupled to a qubit. The device can further comprise a switch device formed across the readout resonator that shifts frequency of the readout resonator based on position of the switch device. According to another embodiment, a device can comprise a bus resonator coupled to a plurality of qubits. The device can further comprise a switch device formed across the bus resonator that shifts frequency of the bus resonator based on position of the switch device.

Systems and methods related to scheduling of tasks for execution in parallel based on geometric reach are described. An example method includes processing information pertaining to connectivity among superconducting components and nodes included in a shared floor plan to generate a plurality of areas of reach, where each of the plurality of areas of reach corresponds to a portion of the shared floor plan. The method further includes generating a plurality of inflated areas of reach by inflating each of the plurality of areas of reach based on a target inductance of wires for routing signals among the superconducting components and the nodes included in the shared floor plan. The method further includes scheduling parallel execution of tasks for routing wires among a subset of the superconducting components and the nodes within any of the plurality of inflated areas of reach satisfying a geometric constraint.

The method of performing braiding operations can include providing a first Josephson junction including first gates. The method can include providing a second Josephson junction including second gates. The method can include tuning the first gates to dispose a first pair of Majorana fermions a first region. The method can include tuning the second gates to dispose a second pair of Majorana fermions in a second region. The method can include tuning the first gates to dispose a first Majorana fermion in the first region and to dispose a second Majorana fermion in a third region. The method can include tuning the second gates to dispose a third Majorana fermion in a fourth region and to dispose a fourth Majorana fermion in the second region.

A composition comprises one or more continuous fibers embedded in a high temperature superconducting material.