A detector for reading out a state of a qubit includes a flux qubit and a flux bias generator. The flux qubit includes an inductor and SQUID loop, in which the flux qubit is arranged to exhibit first and second flux states. The flux bias generator generates a first flux bias through the inductor and a second flux bias through the SQUID loop, such that, in response to a first value of the first flux bias, the energies of the first and the second flux states are substantially identical and, in response to a second value of the first flux bias, the energies of the first and the second flux states are different. In response to a first value of the second flux bias, the flux qubit couples to the qubit and, in response to a second value of the second flux bias, decouples from the qubit and suppresses tunneling.

A device for controlling trapped ions includes a first substrate of a semiconductor and/or dielectric material. A first metal structure is disposed at a main side of the first substrate. The device further includes a second substrate of a semiconductor and/or dielectric material. A second metal structure is disposed at a main side of the second substrate opposite the main side of the first substrate. A spacer is disposed between and bonded to the first and second substrates. The spacer includes an electrical interconnect which electrically connects the first metal structure to the second metal structure. A bond between the spacer and the first substrate or the spacer and the second substrate is a bond formed by waferbonding. At least one ion trap is configured to trap ions in a space between the first and second substrates, the first and second metal structures including electrodes of the ion trap.

A device for controlling trapped ions includes a first substrate of a semiconductor and/or dielectric material. A first metal structure is disposed at a main side of the first substrate. The device further includes a second substrate of a semiconductor and/or dielectric material. A second metal structure is disposed at a main side of the second substrate opposite the main side of the first substrate. A spacer is disposed between and bonded to the first and second substrates. The spacer includes an electrical interconnect which electrically connects the first metal structure to the second metal structure. A bond between the spacer and the first substrate or the spacer and the second substrate is a bond formed by waferbonding. At least one ion trap is configured to trap ions in a space between the first and second substrates, the first and second metal structures including electrodes of the ion trap.

Quantum computing systems and methods are provided. In one example, a quantum computing system includes a quantum system having one or more quantum system qubits and one or more ancilla qubits. The quantum computing system includes one or more quantum gates implemented by the quantum computing system. The quantum gate(s) are operable to configure the one or more ancilla qubits into a known state. The quantum computing system includes a quantum measurement circuit operable to perform a plurality of measurements on the one or more quantum system qubits using the one or more ancilla qubits. The quantum computing system includes one or more processors operable to determine a reduced density matrix for a subset of the quantum system based on a set of the plurality of measurements that include a number of repeated measurements performed using the quantum measurement circuit.

A quantum device capable of preventing contacts from being displaced is provided. A quantum device includes a quantum element in which a quantum circuit is provided, a socket including contacts and a housing, the contacts being in contact with a terminal of the quantum element, and the housing supporting the contacts, and a board including a board substrate. At least one of the housing and the board substrate includes a hole, another one of the housing and the board substrate includes a fixing part disposed inside the hole and a body part other than the fixing part, and the fixing part and the body part are integrally formed.

A quantum device capable of preventing contacts from being displaced is provided. A quantum device includes a quantum element in which a quantum circuit is provided, a socket including contacts and a housing, the contacts being in contact with a terminal of the quantum element, and the housing supporting the contacts, and a board including a board substrate. At least one of the housing and the board substrate includes a hole, another one of the housing and the board substrate includes a fixing part disposed inside the hole and a body part other than the fixing part, and the fixing part and the body part are integrally formed.

In a general aspect, input data for a computer process are preprocessed by a preprocessor unit that includes a quantum processor. In some aspects, a preprocessor unit obtains input data for a computer process that is configured to run on a computer processing unit. Randomized parameter values are computed for variable parameters of a quantum logic circuit based on the input data. A classical processor in the preprocessor unit computes the randomized parameter values from the input data and a set of random numbers. A quantum processor in the preprocessor unit produces quantum processor output data by executing the quantum logic circuit having the randomized parameter values assigned to the variable parameters. Preprocessed data generated based on the quantum processor output data are then provided as the input for the computer process configured to run on the computer processing unit.

A quantum device includes a substrate including a first material and including an upper surface thereof, a first layer comprising a compound of the first material disposed on the upper surface of the substrate, a second layer, comprising a metal oxide, disposed on the first layer, a third layer, comprising a noble metal, disposed on the second layer, a fourth layer, comprising a metal oxide, disposed on the third layer, a fifth layer, comprising a piezoelectric material, disposed on the fourth layer, a sixth layer, comprising a noble metal, disposed on the fifth layer, a seventh layer, comprising a material capable of quantum emission, disposed on the sixth layer, and an eighth layer, comprising a noble metal, disposed on the seventh layer, and at least one of the eighth layer and the seventh layer are sized to enable quantum emission from the seventh layer.

A system includes N-distant independent plasmonic graphene waveguides. The N-distant independent plasmonic graphene waveguides are used to generate an N-partite continuous variable entangled state.

Provided is a three-dimensional (3D) transmon qubit apparatus including a body portion, a driver, a transmon element disposed in an internal space of the body portion, a first tunable cavity module disposed in the internal space of the body, and comprising a first superconductive metal panel; and a second tunable cavity module disposed in the internal space of the body, and comprising a second superconductive metal panel, wherein the transmon element is disposed between the first superconductive metal panel and the second superconductive metal panel; wherein the first tunable cavity module and the second tunable cavity module are configured to adjust a distance between the first superconductive metal panel and the second superconductive metal panel, and wherein the driver is configured to tune a resonance frequency by adjusting a 3D cavity by adjusting the distance between the first superconductive metal panel and the second superconductive metal panel.