A technique relates to a structure. A first surface includes an inductive element of a resonator. A second surface includes a first portion of a capacitive element of the resonator and at least one qubit. A second portion of the capacitive element of the resonator is on the first surface.

Described herein are methods that allow reducing or eliminating formation of silicon nitride layers at superconductor-silicon interfaces, as well as quantum circuit devices fabricated using such methods. The methods include applying various surface modification techniques to silicon in order to form a controlled interfacial layer at the interface of silicon and superconductor, which interfacial layer prevents or at least minimizes formation of silicon nitride at said interface. Reducing or eliminating silicon nitride layers at superconductor-silicon interfaces in quantum circuits may help minimizing the negative effects of spurious TLS's, thereby improving on the decoherence problem of qubits.

A process for producing a cube textured foil is described. The process includes providing a cube textured metal foil M. The process further includes electroplating an epitaxial layer of an alloy on the foil M, whereby the epitaxial layer substantially replicates the cube texture of the metal foil M. The process further includes electroplating a non-epitaxial layer of an alloy on the epitaxial layer. The process further includes separating the electroplated alloy from the cube textured metal foil M to obtain an electro-formed alloy with one cube textured surface.

A method of fabricating a device including a superconductive layer includes depositing a seed layer on a substrate at a first temperature, the seed layer being a nitride of a first metal, reducing the temperature of the substrate to a second temperature that is lower than the first temperature, increasing the temperature of the substrate to a third temperature that is higher than the first temperature to form a modified seed layer, and depositing a metal nitride superconductive layer directly on the modified seed layer at the third temperature, the superconductive layer being a nitride of a different second metal.

The invention relates to a method of producing a solid-state component, in particular for a quantum component, preferably for a qubit, comprising one or more thin films, the one or more thin films comprising a first material and each said film having a thickness selected between a monolayer and 100 nm and is deposited onto a substrate surface of a substrate, wherein the production process is carried out in a reaction chamber sealed with respect to the ambient atmosphere. Further, the invention relates to a solid-state component, in particular for a quantum component, preferably for a qubit, comprising one or more thin films, one of the one or more thin films comprises a first material with a thickness between a monolayer and 100 nm and is deposited onto a substrate surface of a substrate. In addition, the invention relates to a quantum component comprising such a solid-state component according to the present invention and to an apparatus for producing such a solid-state component according to the present invention.

The present invention discloses the low-stress niobium nitride (NbN) superconducting thin film and preparation method and application thereof. The preparation method includes the following steps: providing the metal Nb target and the Si-based substrates, fixing the Si-based substrate at room temperature, adjusting the mass flow ratio of N.sub.2/Ar to 20%-50%, the sputtering power to 50-400 W and the deposition pressure to 3.0-10.0 mTorr, NbN superconducting thin films with a stress range of-500 MPa?500 MPa and a thickness of 70-150 nm were deposited on Si-based substrates. By synergistically controlling the mass flow rate ratio of N.sub.2/Ar, sputtering power, and deposition pressure, low stress NbN superconducting thin films can be easily and efficiently prepared. The stress range of the prepared NbN superconducting thin films meets the preparation requirements of superconducting dynamic inductance detectors, and can be mass-produced.

A method of fabricating a device including a superconductive layer includes depositing a seed layer on a substrate, exposing the seed layer to an oxygen-containing gas or plasma to form a modified seed layer, and after exposing the seed layer to the oxygen-containing gas or plasma depositing a metal nitride superconductive layer directly on the modified seed layer. The seed layer is a nitride of a first metal, and the superconductive layer is a nitride of a different second metal.

Techniques that can facilitate high-transparency semiconductor-metal interfaces are provided. In one example, a method can comprise forming a silicon on insulator (SOI) over a wafer. The method can further comprise depositing a metal on the SOI. The method can further comprise forming a structure by dry-etching the metal and dry-etching the SOI. The method can further comprise forming a template over the structure. The method can further comprise etching a portion of the SOI for removal under the metal. The method can further comprise growing a semiconductor where the portion of SOI was removed.

A superconducting integrated circuit includes at least one superconducting resonator, including a substrate, a conductive layer disposed over a surface of the substrate with the conductive layer including at least one conductive material including a substantially low stress polycrystalline Titanium Nitride (TiN) material having an internal stress less than about two hundred fifty MPa (magnitude) such that the at least one superconducting resonator and/or qubit (hereafter called device) is provided as a substantially high quality factor, low loss superconducting device.

An integrated, superconducting imaging sensor may be formed from a single, meandering nanowire. The sensor is capable of single-photon (or single-event) detection and imaging with ?10 micron spatial resolution and sub-100-picosecond temporal resolution. The sensor may be readily scaled to large areas.