A method for measuring conductance of a material real-time during etching/milling includes providing a fixture having a socket for receiving the material. The socket is attached to a printed circuit board (PCB) mounted on one side of a plate that has at least one opening for providing ion beam access to the material sample. Conductive probes extend from the other side of the PCB to contact and span a target area of the material. A measurement circuit in electrical communication with the probes measures the voltage produced when a current is applied across the material sample to measure changes in electrical properties of the sample over time.

Systems and techniques facilitating antenna-based thermal annealing of qubits are provided. In one example, a radio frequency emitter, transmitter, and/or antenna can be positioned above a superconducting qubit chip having a Josephson junction coupled to a set of one or more capacitor pads. The radio frequency emitter, transmitter, and/or antenna can emit an electromagnetic signal onto the set of one or more capacitor pads. The capacitor pads can function as receiving antennas and therefore receive the electromagnetic signal. Upon receipt of the electromagnetic signal, an alternating current and/or voltage can be induced in the capacitor pads, which current and/or voltage thereby heat the pads and the Josephson junction. The heating of the Josephson junction can change its physical properties, thereby annealing the Josephson junction. In another example, the emitter can direct the electromagnetic signal to avoid unwanted annealing of neighboring qubits on the superconducting qubit chip.

A thermalization structure is formed using a foil and a low temperature device (LTD). The foil includes a first layer of a first material. The LTD includes a surface from which heat is transferred away from the LTD. A coupling is formed between the foil and the surface of the LTD, where the coupling includes a bond formed between the foil and the surface such that forming the bond forms a set of ridges in the foil, a ridge in the set of ridges operating to dissipate the heat.

A structure including a plurality of laser discharge structures located on a planar lightwave circuit, and a single laser source connected to each of the plurality of laser discharge structures by one or more Mach Zehnder switches and a plurality of optical connections.

Disclosed are a superconductor having improved critical current density when exposed to high-energy neutron radiation and high magnetic fields, such as found in a compact nuclear fusion reactor, and a method of making the same. The method includes, prior to deployment in the exposure environment, irradiating a polycrystalline (e.g. cuprate) superconductor with ionic matter or neutrons at a cryogenic temperature to create weak magnetic flux pinning sites, such as point defects or small defect clusters. Irradiation temperature is chosen, for example as a function of the superconducting material, so that irradiation creates the beneficial flux pinning sites while avoiding detrimental widening of the boundaries of the crystalline grains caused by diffusion of the displaced atoms. Such a superconductor in a coated-conductor tape is expected to be beneficial when used, for example, as a toroidal field coil in a fusion reactor when cooled well below its critical temperature.

A method of fabricating a superconducting-semiconducting stack includes cleaning a surface of a substrate, the substrate comprising a group IV element; depositing an insulating buffer layer onto the substrate, the insulating buffer layer comprising the group IV element; depositing a p-doped layer onto the insulating buffer layer; depositing a diffusion barrier onto the p-doped layer; and processing the superconducting-semiconducting stack through dopant activation.

A method of an embodiment includes forming a capacitor pad for a nonlinear resonator. In an embodiment, the method includes comparing a resonance frequency of the nonlinear resonator to a target frequency to determine whether the resonance frequency falls within a range of the target frequency. A device of an embodiment includes a first capacitor pad comprising a superconducting material, the first capacitor pad configured to couple to a first end of a logic circuit element. In an embodiment, the device includes a second capacitor pad comprising a second superconducting material, the capacitor pad configured to couple to a second end of the logic circuit element. In an embodiment, the second capacitor pad includes a first portion; a second portion; and a bridge configured to electrically connect the first portion and the second portion.

Systems and techniques facilitating antenna-based thermal annealing of qubits are provided. In one example, a radio frequency emitter, transmitter, and/or antenna can be positioned above a superconducting qubit chip having a Josephson junction coupled to a set of one or more capacitor pads. The radio frequency emitter, transmitter, and/or antenna can emit an electromagnetic signal onto the set of one or more capacitor pads. The capacitor pads can function as receiving antennas and therefore receive the electromagnetic signal. Upon receipt of the electromagnetic signal, an alternating current and/or voltage can be induced in the capacitor pads, which current and/or voltage thereby heat the pads and the Josephson junction. The heating of the Josephson junction can change its physical properties, thereby annealing the Josephson junction. In another example, the emitter can direct the electromagnetic signal to avoid unwanted annealing of neighboring qubits on the superconducting qubit chip.

Systems and techniques facilitating antenna-based thermal annealing of qubits are provided. In one example, a radio frequency emitter, transmitter, and/or antenna can be positioned above a superconducting qubit chip having a Josephson junction coupled to a set of one or more capacitor pads. The radio frequency emitter, transmitter, and/or antenna can emit an electromagnetic signal onto the set of one or more capacitor pads. The capacitor pads can function as receiving antennas and therefore receive the electromagnetic signal. Upon receipt of the electromagnetic signal, an alternating current and/or voltage can be induced in the capacitor pads, which current and/or voltage thereby heat the pads and the Josephson junction. The heating of the Josephson junction can change its physical properties, thereby annealing the Josephson junction. In another example, the emitter can direct the electromagnetic signal to avoid unwanted annealing of neighboring qubits on the superconducting qubit chip.

Symmetrical qubits with reduced far-field radiation are provided. In one example, a qubit device includes a first group of superconducting capacitor pads positioned about a defined location of the qubit device, wherein the first group of superconducting capacitor pads comprise two or more superconducting capacitor pads having a first polarity, and a second group of superconducting capacitor pads positioned about the defined location of the qubit device in an alternating arrangement with the first group of superconducting capacitor pads, wherein the second group of superconducting capacitor pads comprise two or more superconducting capacitor pads having a second polarity that is opposite the first polarity.