Abstract: Methods, systems and apparatus for correcting a result of a quantum computation.

Abstract: Methods, systems and apparatus for correcting a result of a quantum computation.

Abstract: Methods, systems and apparatus for correcting a result of a quantum computation.

Abstract: The disclosure is directed to characterizing a quantum logic circuit (QLC), via a set of intrinsic parameters. One method includes selecting control vectors that are associated with phase shifts for the intrinsic parameters such that experimental unitary operators for the QLC are defined. Each experimental unitary operator is based on the intrinsic parameters and phase shifts associated with a corresponding control vector. For each control vector, eigenvalues for the corresponding unitary operator are estimated based on qubit measurements performed subsequent to tuning the QLC in accordance with the control vector. The eigenvalues correspond to quasienergy levels of the qubits. Values for the set of intrinsic parameters may be determined based on the eigenvalues.

Abstract: The disclosure is directed to characterizing a quantum logic circuit (QLC), via a set of intrinsic parameters. One method includes selecting control vectors that are associated with phase shifts for the intrinsic parameters such that experimental unitary operators for the QLC are defined. Each experimental unitary operator is based on the intrinsic parameters and phase shifts associated with a corresponding control vector. For each control vector, eigenvalues for the corresponding unitary operator are estimated based on qubit measurements performed subsequent to tuning the QLC in accordance with the control vector. The eigenvalues correspond to quasienergy levels of the qubits. Values for the set of intrinsic parameters may be determined based on the eigenvalues.

Abstract: Methods, systems and apparatus for error correction of fermionic quantum simulation. In one aspect, a method includes representing a fermionic system as a graph of vertices and edges, where each vertex represents a fermionic system fermionic mode and each edge represents an interaction between two respective fermionic modes; allocating a qubit to each edge in the graph to form a qubit system; determining qubit operators that satisfy a set of fermionic commutation and dependence relations, where the qubit operators are non-uniform with respect to the graph vertices; determining stabilizer operators corresponding to products of quadratic Majorana operators on respective loops in the graph, where a common eigenspace of the defined stabilizer operators defines a code subspace that encodes states of the fermionic system to be simulated; and simulating the fermionic system by evolving the qubit system under a qubit Hamiltonian that includes the determined qubit operators and stabilizer operators.

Abstract: Systems and methods for quantum computing devices are provided. In one example, a method may include preparing one or more qubits in a selected initial state of a set of initial states. The method may include implementing a first quantum circuit for n repetitions on the one or more qubits, the first quantum circuit comprising one or more quantum gates. The method may include implementing a second quantum circuit to map a state of the one or more qubits towards a target state, the second quantum circuit based on a unitary associated with the first quantum circuit. The method may include performing a measurement of the one or more qubits. The method may include determining a fidelity between the first quantum circuit and the unitary based at least in part on the measurement of the one or more qubits.

Abstract: A method of fabricating a refractive optical element on a substrate may provide less expensive and more compact optics for an X-ray system. The method includes coating the substrate with a resin and providing radiation to a portion of the resin to cause two photon polymerization of the resin. The method further includes forming, by two photon polymerization, a first surface of a polymer refractive optical element from the resin. The first surface is disposed along an optical axis of the refractive optical element and the first surface has a roughness of less than 100 nanometers. Further, the method includes forming, by two photon polymerization, a second surface of the polymer refractive optical element. The second surface is disposed along the optical axis of the refractive optical element and the second surface has a roughness of less than 100 nanometers.

Abstract: Methods, systems and apparatus for correcting a result of a quantum computation.

Abstract: Methods, systems and apparatus for correcting a result of a quantum computation.

Abstract: 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.

Abstract: Provided is a vehicle measurement system for an automatic conveyor. The measurement system includes: an information measurement unit, disposed at a position higher than the ready-for-loading vehicle and including two laser radars: a rear radar and a side radar; a voice prompt unit, configured to send a voice prompt; and a control unit; where when the ready-for-loading vehicle is approaching, the rear radar measures a distance between it and the ready-for-loading vehicle in real time as a predetermined parking distance; when a value of the predetermined parking distance is within a predetermined range, the control unit controls the voice prompt unit to send a voice prompt for parking; and after the ready-for-loading vehicle stops, the information measurement unit measures the distance between the ready-for-loading vehicle and the rear radar, carriage size information, and a deviation angle of a parking position of the ready-for-loading vehicle from the predetermined parking area.

Abstract: 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.

Abstract: A method of fabricating a refractive optical element on a substrate may provide less expensive and more compact optics for an X-ray system. The method includes coating the substrate with a resin and providing radiation to a portion of the resin to cause two photon polymerization of the resin. The method further includes forming, by two photon polymerization, a first surface of a polymer refractive optical element from the resin. The first surface is disposed along an optical axis of the refractive optical element and the first surface has a roughness of less than 100 nanometers. Further, the method includes forming, by two photon polymerization, a second surface of the polymer refractive optical element. The second surface is disposed along the optical axis of the refractive optical element and the second surface has a roughness of less than 100 nanometers.

Abstract: Methods, systems and apparatus for correcting a result of a quantum computation.

Abstract: Methods, systems and apparatus for error correction of fermionic quantum simulation. In one aspect, a method includes representing a fermionic system as a graph of vertices and edges, where each vertex represents a fermionic system fermionic mode and each edge represents an interaction between two respective fermionic modes; allocating a qubit to each edge in the graph to form a qubit system; determining qubit operators that satisfy a set of fermionic commutation and dependence relations, where the qubit operators are non-uniform with respect to the graph vertices; determining stabilizer operators corresponding to products of quadratic Majorana operators on respective loops in the graph, where a common eigenspace of the defined stabilizer operators defines a code subspace that encodes states of the fermionic system to be simulated; and simulating the fermionic system by evolving the qubit system under a qubit Hamiltonian that includes the determined qubit operators and stabilizer operators.

Abstract: Methods, systems and apparatus for simulating physical systems. In one aspect, a method includes the actions of selecting a first set of basis functions for the simulation, wherein the first set of basis functions comprises an active and a virtual set of orbitals; defining a set of expansion operators for the simulation, wherein expansion operators in the set of expansion operators approximate fermionic excitations in an active space spanned by the active set of orbitals and a virtual space spanned by the virtual set of orbitals; performing multiple quantum computations to determine a matrix representation of a Hamiltonian characterizing the system in a second set of basis functions, computing, using the determined matrix representation of the Hamiltonian, eigenvalues and eigenvectors of the Hamiltonian; and determining properties of the physical system using the computed eigenvalues and eigenvectors.

Abstract: Systems and methods for composite quantum gate calibration for a quantum computing system are provided. In some implementations, a method includes accessing a unitary gate model describing a composite quantum gate. The unitary gate model includes a plurality of gate parameters. The method includes implementing the composite quantum gate for a plurality of gate cycles on the quantum system to amplify the plurality of gate parameters. The method includes obtaining a measurement of a state of the quantum system after implementing the composite quantum gate for the plurality of gate cycles. The method includes determining at least one of the plurality of gate parameters based at least in part on the measurement of the state of the quantum system. The method includes calibrating the composite quantum gate for the quantum computing system based at least in part on the plurality of gate parameters.

Abstract: Methods, systems and apparatus for preparing arbitrary superposition quantum states of a quantum register on a quantum computer, the quantum state comprising a superposition of L computational basis states. In one aspect, a register of log L qubits is prepared in a weighted sum of register basis states, where each register basis state indexes a corresponding quantum state computational basis state, and the amplitude of each register basis state in the weighted sum of register basis states is equal to the amplitude of the corresponding computational basis state in the superposition of L computational basis states. A unitary transformation that maps the register basis states to the corresponding L computational basis states is then implemented, including, for each index 1 to L, controlling, by the register of log L qubits, transformation of the quantum system register state for the index to the corresponding computational basis state for the index.

Abstract: Provided is a vehicle measurement system for an automatic conveyor. The measurement system includes: an information measurement unit, disposed at a position higher than the ready-for-loading vehicle and including two laser radars: a rear radar and a side radar; a voice prompt unit, configured to send a voice prompt; and a control unit; where when the ready-for-loading vehicle is approaching, the rear radar measures a distance between it and the ready-for-loading vehicle in real time as a predetermined parking distance; when a value of the predetermined parking distance is within a predetermined range, the control unit controls the voice prompt unit to send a voice prompt for parking; and after the ready-for-loading vehicle stops, the information measurement unit measures the distance between the ready-for-loading vehicle and the rear radar, carriage size information, and a deviation angle of a parking position of the ready-for-loading vehicle from the predetermined parking area.