According to an embodiment of the present invention, a method of producing a computing device includes providing a semiconductor substrate, and patterning a mask on the semiconductor substrate, the mask exposing a first portion of the semiconductor substrate and covering a second portion of the semiconductor substrate. The method includes implanting the first portion of the semiconductor substrate with a dopant. The method includes annealing the first portion of the semiconductor substrate to form an annealed doped region, while maintaining the second portion of the semiconductor substrate as an unannealed portion.

An exemplary tundable capacitor in a quantum system includes a pair of qubits, and a capacitive coupling element coupled between the pair of qubits. The capacitive coupling element includes a plurality of gate terminals. The capacitive coupling element is configured to receive a respective gate voltage at each of the plurality of gate terminals and to adjust a capacitance of the capacitive coupling element in response to the respective gate voltage received at each of the plurality of gate terminals. The capacitance of the capacitive coupling element is configured to control a coupling strength between the pair of qubits.

A connection structure for a superconducting layer according to an embodiment includes a first superconducting layer; a second superconducting layer; and a connection layer disposed between the first superconducting layer and the second superconducting layer, the connection layer including crystal grains containing a rare earth element (RE), barium (Ba), copper (Cu), and oxygen (O), the crystal grains having a grain size distribution including a bimodal distribution. The bimodal distribution includes a first distribution including a first peak and a second distribution including a second peak. A first grain size corresponding to the first peak is larger than a second grain size corresponding to the second peak. Among the crystal grains, crystal grains having a grain size corresponding to the first distribution include a crystal grain having a plate shape or a flat shape.

According to the present invention, a piezoelectric film having a single crystal structure is able to be formed, from various piezoelectric materials, on a film structure of the present invention. A film structure according to the present invention includes: a substrate; a buffer film which is formed on the substrate and has a tetragonal crystal structure containing zirconia; a metal film containing a platinum group element, which is formed on the buffer film by means of epitaxial growth; and a film containing Sr(Ti.sub.1−x, Ru.sub.x)O.sub.3 (wherein 0≤x≤1), which is formed on the metal film by means of epitaxial growth.

Superconducting metamaterials composed of lumped-element inductors and capacitors are used to implement microwave photonics with novel dispersion relations and dense mode spectra that can be coupled to qubits. Metamaterial lattices may have qubits coupled to different unit cells in the metamaterial such that each qubit will couple strongly to modes with an antinode at the qubit location. Through simultaneous driving of combinations of modes, large amplitudes are produced at only one or a few unit cells, resulting in large ac Stark shifts of qubits located there, and providing a frequency-addressable qubit array without requiring flux-tunability and with reduced control wiring.

Techniques regarding qubit structures comprising ion implanted Josephson junctions are provided. For example, one or more embodiments described herein can comprise an apparatus that can include a strip of superconducting material coupling a first superconducting electrode and a second superconducting electrode. The strip of superconducting material can have a first region comprising an ion implant and a second region that is free from the ion implant.

A Josephson junction device includes a planar arrangement including a first two-dimensional (2D) material layer, a graphene layer, and a second 2D material layer planarly arranged on a device substrate, the first 2D material layer including at least one layer of a 2D material, the graphene layer forming a first junction with the first 2D material layer, and the second 2D material layer forming a second junction with the graphene layer and including at least one layer of a 2D material. A distance between the first junction and the second junction is within a range configured to cause a Josephson effect.

According to an embodiment of the present invention, a method of producing a computing device includes providing a semiconductor substrate, and patterning a mask on the semiconductor substrate, the mask exposing a first portion of the semiconductor substrate and covering a second portion of the semiconductor substrate. The method includes implanting the first portion of the semiconductor substrate with a dopant. The method includes annealing the first portion of the semiconductor substrate to form an annealed doped region, while maintaining the second portion of the semiconductor substrate as an unannealed portion.

One example includes a magnetic Josephson junction (MJJ) system. The system includes a first superconducting material layer and a second superconducting material layer each configured respectively as a galvanic contacts. The system also includes a ferrimagnetic material layer arranged between the first and second superconducting material layers and that is configured to exhibit a fixed net magnetic moment at a predetermined operating temperature of the MJJ system. The system also includes a ferromagnetic material layer arranged between the first and second superconducting material layers and that is configured to exhibit a variable magnetic orientation in response to an applied magnetic field. The MJJ system can be configured to store a binary logical value based on a direction of the variable magnetic orientation of the ferromagnetic material layer. The system further includes a spacer layer arranged between the ferromagnetic and the ferrimagnetic material layers.

Josephson junction (JJ) structures are disclosed. In some embodiments, a JJ structure may include a non-superconducting structure having a hollow region. A first superconducting structure may be disposed inside the hollow region of the non-superconducting structure, and a second superconducting structure may be disposed around the non-superconducting structure outside the hollow region.