University of Toronto

University of Southern California

D-wave Systems Inc.

Magiq Technologies, Inc.

Daniel A Lidar

Lian-Ao Wu

Alexandre Blais

Walter Vinci

David L Bacon

K Birgit Whaley

Tameem Albash

Julia Kempe

An optimally stopped heuristic optimizer includes a processor. The processor heuristically generates a sequence of proposed solutions for solving a discrete optimization problem associated with an objective function, and for each additional proposed solution of the sequence, derives an estimate of a quality distribution that is based on the sequence including the additional proposed solution. The quality distribution assigns a probability to each of the proposed solutions according to quality of the proposed solution. The processor further, responsive to a most recent additional proposed solution of the sequence having quality better than a quality threshold that is defined by the estimate corresponding to the sequence including the most recent additional proposed solution, commands a stop such that further proposed solutions to the discrete optimization problem are no longer generated, and identifies and outputs a selected one of the sequence having best quality.

Optimally stopped optimization systems having heuristic optimizer and methods using the same

Systems and methods of processing using a quantum processor are described. A method includes obtaining a problem Hamiltonian and defining a nested Hamiltonian with a plurality of logical qubits by embedding a logical Krepresenting the problem Hamiltonian into a larger K, where N represents a number of the logical qubits and C represents a nesting level defining the amount of hardware resources for the nest Hamiltonian. The method also includes encoding the nested Hamiltonian into the plurality of physical qubits of the quantum processor; and performing a quantum annealing process with the quantum processor after the encoding.

Nested quantum annealing correction

A quantum computing method comprising constructing a dressing transformation V between a physical Hamiltonian H and an ideal Hamiltonian H. The physical Hamiltonian H describes a physical quantum computer that comprises a plurality of qubits, including interactions between the plurality of qubits and a continuum. The ideal Hamiltonian Hdescribes the universal quantum computer that corresponds to the physical quantum computer. Each qubit in the plurality of qubits is initialized and quantum calculations are performed using the plurality of qubits. Measurement of the plurality of qubits is performed in the dressed state.

Dressed qubits

The present invention involves a quantum computing structure, comprising: one or more logical qubits, which is encoded into a plurality of superconducting qubits; and each of the logical qubits comprises at least one operating qubit and at least one ancilla qubit. Also provided is a method of quantum computing, comprising: performing encoded quantum computing operations with logical qubits that are encoded into superconducting operating qubits and superconducting ancilla qubits. The present invention further involves a method of error correction for a quantum computing structure comprising: presenting a plurality of logical qubits, each of which comprises an operating physical qubit and an ancilla physical qubit, wherein the logical states of the plurality of logical qubits are formed from a tensor product of the states of the operating and ancilla qubits; and wherein the states of the ancilla physical qubits are suppressed; and applying strong pulses to the grouping of logical qubits.

Encoding and error suppression for superconducting quantum computers

The invention includes systems for and methods of performing quantum computation. The method of quantum computation includes preparing a set of one or more qubits capable of storing quantum information in 2possible states, wherein the number of qubits n&#x2267;1. The qubit set is subject to a decoherence mechanism that could cause a loss of quantum information stored in some but not all of the qubit states. The method also includes determining, via a quantum measurement of the qubit system or just by analyzing the decoherence of the qubit states, which of the 2states or their superposition is/are not susceptible to decoherence. The method further includes encoding and processing quantum information in one or more of the decoherence-free states by controlling qubit-qubit interactions or via an electromagnetic interaction with the set of qubits.

Quantum computation

A method for performing a single-qubit gate on an arbitrary quantum state. An ancillary qubit is set to an initial state |I&#x3e;. The data qubit is coupled to an ancillary qubit. The state of the ancillary qubit is measured, and the data qubit and the ancillary qubit are coupled for a first period of time. A method for applying a single-qubit gate to an arbitrary quantum state. A state of a first and second ancillary qubit are set to an entangled initial state |I&#x3e;. A state of a data qubit and the first ancillary qubit are measured thereby potentially performing a single qubit operation on the arbitrary quantum state. A first result is determined. The first result indicates whether the single qubit operation applied the single qubit gate to the arbitrary quantum state.

Growing community of inventors

La Canada, CA, United States of America

Daniel A Lidar