90 results about "Quantum system" patented technology

The invention provides a quantum system data processing method based on light quantum and a light quantum computer, and the method comprises the steps: obtaining an ordinary differential equation and the attribute information of the ordinary differential equation; according to the frequency spectrum number of the ordinary differential equation and the attribute information of the ordinary differential equation, constructing an initial light quantum circuit corresponding to the ordinary differential equation; measuring the initial light quantum circuit, and determining a target function corresponding to the initial light quantum circuit according to a measurement result; loss information of the target function is determined, whether the initial light quantum circuit is applied or not is determined according to the loss information, and if yes, the initial light quantum circuit serves as a target light quantum circuit; and performing operation on input data of the quantum system based on the target light quantum line. According to the method, the light quantum circuit expression capability can be greatly improved, and high-precision solving of the ordinary differential equation is realized.

A method includes receiving a plurality of quantum systems, wherein each quantum system of the plurality of quantum system includes a plurality of quantum sub-systems in an entangled state, and wherein respective quantum systems of the plurality of quantum systems are independent quantum systems that are not entangled with one another. The method further includes performing a plurality of joint measurements on different quantum sub-systems from respective ones of the plurality of quantum systems, wherein the joint measurements generate joint measurement outcome data and determining, by a decoder, a plurality of syndrome graph values based on the joint measurement outcome data.

The present disclosure provides a method for searching at least one locally marked element defined by marking parameters within a 2D lattice of a quantum system, wherein the quantum system is operated in discrete time and wherein the 2D lattice is arranged for supporting quantum random walks which are defined by quantum random walk parameters, the method having a pre-set time comprises the steps of calibrating the quantum system by: initializing a quantum state in the quantum system on at least one node; performing one step of the split-step quantum random walk on the quantum state; obtaining probability density information of the quantum state through overlap with eigenstates of a unitary operator; repeating previous two steps to determine quantum random walk parameters based on the highest probability in the probability density information of the quantum state. Thereafter, the method comprises the steps of searching the quantum system for the at least one marked element by: tuning the marking parameters of the at least one locally marked element; initializing a uniformly distributed quantum state on the entire quantum system; performing a plurality of split-step quantum random walks for the uniformly distributed quantum state; after the pre-set time has lapsed, converting the uniformly distributed quantum state of step vii) into an observable.

The invention relates to a quantum system (1) for stabilizing a cat qubit comprising: - a command circuit (5) including a microwave source (11) and a DC voltage source (13), and - a non-linear superconducting quantum circuit (3) including a non-linear element (7) comprising a Josephson junction, a first and a second resonant portions respectively having a first mode with a first resonant frequency fa and a second mode with a second resonant frequency fb. The non-linear superconducting quantum circuit (3) stabilizes a two-dimensional manifold hosting the cat qubit when: • the microwave source (11) delivers microwave radiation at a frequency equal to fb to the second resonant portion to drive the second mode, and • the DC voltage source (13) delivers DC voltage to bias the non-linear element (7), with the delivered DC voltage having a value inducing a microwave oscillation having a frequency equal to |2fa - fb|.

A quantum simulation method for solving a computational problem using a solid-state quantum system, the method comprising the steps of: passing a laser through a material; in the material, evolving at least some of a plurality of atoms in a first state into at least some of a plurality of atoms in a second state upon receiving energy from the laser to form at least one exciton; selecting at least one exciton site on the material wherein the at least one exciton site is separated from a neighbouring at least one exciton site by a distance less than a Rydberg blockade radius; mapping the computational problem into a problem Hamiltonian of the solid-state quantum system; measuring at least a portion of plurality of the at least one excitons to obtain a read-out of the solid-state quantum system; and determining a solution to the computational problem from the read-out.

The present disclosure relates to a non-Hermitian quantum sensing circuit and a sensing system. The non-Hermitian quantum sensing circuit comprises at least one sensing unit, wherein the sensing unit comprises an input end, an output end, and an N-dimensional N-order quantum system cascaded between the input end and the output end, wherein N is a positive integer greater than or equal to 2, and the N-dimensional N-order quantum system is configured to form a topological adiabatic effect quantum state between the input end and the output end to receive an external disturbance signal. The present disclosure can not only have a wider range of detectable physical quantities, but also achieve a further order of magnitude improvement in sensitivity, while effectively solving the problem of unstable signal-to-noise ratio caused by the improvement in sensitivity.

In a method for influencing an operating state of a quantum system, the quantum system comprises at least one defect, defect complex or impurity in a host material. A transition between different energy levels of the at least one defect, defect complex or impurity is determined. The transition has a transition energy that is a function of an external electric field and / or external mechanical stress. The transition energy has a critical point. A bias electric field and / or a bias mechanical stress is determined for bringing the transition energy of the at least one defect, defect complex or impurity to or close to the critical point. The external electric field comprises the bias electric field and an environmental noise electric field. The external mechanical stress comprises the bias mechanical stress and an environmental noise mechanical stress. The determined bias electric field and / or mechanical stress is applied to the quantum system.

Provided are quantum control methods and systems. The method includes generating a control pulse in a quantum system, determining a measurement of a state of the quantum system in response to the control pulse, determining a control pulse correction based on the control pulse, the measurement of the state of the quantum system, and a model reference state, modifying the control pulse based on the control pulse correction, resulting in a modified control pulse, and generating the modified control pulse in the quantum system.

The present invention provides a quantum system error detection device, the device comprising: a control register for receiving information representing a quantum state of a control qubit and outputting an operation result; an auxiliary register for receiving, on a one-to-one basis, information representing a quantum state of a target qubit; a CNOT gate connected to the control register and the auxiliary register; a first detector connected to the control register and configured to measure a quantum state of the control qubit to which the CNOT gate is applied; a second detector connected to the auxiliary register and configured to measure a quantum state of the auxiliary qubit to which the CNOT gate is applied; a probability calculation unit for calculating probabilities of quantum states of the control qubit and the target qubit from measurement results of the first detector and the second detector; and an error rate calculation unit for calculating error rates of quantum state initialization, the CNOT gate, and quantum measurement from the probabilities calculated by the probability calculation unit.

The invention relates to a method for generating a useful signal (11) from a signal (5') emitted from a spin-based quantum system (4), said method including exciting the spin-based quantum system (4) by means of an excitation light (13), exciting the spin-based quantum system (4) by means of an electromagnetic field (3) which jumps back and forth between two measurement frequencies at a modulation frequency, the two measurement frequencies having a first measurement frequency distance from an expected resonant frequency, detecting the signal (5') emitted from the spin-based quantum system (4) in order to obtain a measurement signal (7), multiplying the measurement signal (7) by a modulation signal (9) which jumps back and forth between two modulation signal states at the modulation frequency in order to generate a modulated measurement signal (7'), demodulating the modulated measurement signal (7') in order to generate the useful signal (11), determining a comparison signal, and determining whether the expected resonant frequency value is correct based on the comparison signal.

A quantum error correction system that can realize a scheme which, when the quantum system suffers some noise, the quantum system itself can act on itself to correct itself against this noise is provided. The quantum error correction system includes a quantum material and a bi-chromatic recovery drive generator in communication with the quantum material. The bi-chromatic recovery drive generator sends a waveform to the quantum material.

The invention discloses a quantum fidelity estimation method based on a resonance algorithm, and relates to the technical field of quantum computing, and the method comprises the steps: providing a target quantum system with the fidelity to be estimated and a detection quantum bit, initializing the detection quantum bit into a preset energy eigenstate, and enabling the target quantum system to be a quantum state prepared by an experiment; coupling the two to form a coupling system; controlling the coupling system to evolve for a preset time under a preset resonance Hamiltonian; measuring the probability that the detection quantum bit is in a preset excited state; frequency sweeping parameters in the resonance Hamiltonian are adjusted, evolution and measurement are repeated, when the frequency sweeping parameters are matched with the target energy level corresponding to the target quantum system, a peak value appears in the excited state probability, and the peak value is the fidelity of the target quantum system and the quantum state corresponding to the target energy level. According to the method, a large amount of multi-bit measurement is not needed, quantum fidelity estimation can be realized only through single-bit measurement, the measurement times are reduced, and the measurement realization difficulty is reduced.

A method (100) for determining a ground state (1000) of a quantum system is disclosed, comprising the following steps: 6) determining (102) the thermal state (1020) of the quantum system at a temperature value (1001', 1001) by optimizing the free energy (3020) of the thermal state (1020) at the temperature value (1001', 1001) by iteratively adjusting gate parameters (1022', 1022) by means of a variational quantum thermalizer (1010) until a first termination criterion is met; 7) checking (1025) whether the previously found thermal state meets a second termination criterion; 8) if the second termination criterion is not met (10250): decreasing (1026) the temperature value (1001', 1001); initializing (301) the quantum circuit (1011) of the variational quantum thermalizer using the gate parameters (1022', 1022) from the last iteration of step 2); repeating steps 2) and 3); 9) if the second termination criterion is met (10251): providing (103) an energy spectrum (1030) of the quantum system using the gate parameters (1022) of the last iteration of step 2) before the second termination criterion (10251) is met; determining (104) the ground state (1000) of the quantum system by selecting the state of the energy spectrum that is assigned the lowest energy.

The invention relates to a method for calibrating a two-level spin quantum system in the form of a double quantum dot comprising a left dot and a right dot, coupled to a microwave cavity by symmetric and antisymmetric magnetic fields, the system being subjected to a bias voltage, the method being characterized by the steps of: - setting the bias voltage (ε) to zero volts, - determining the wave function φp of each of the quantum dots, - calculating and / or setting the antisymmetric magnetic coupling constant αas and the symmetric magnetic coupling constant αs, calculating and / or setting the tunnel coupling constant and / or the symmetric magnetic coupling constant αs and / or the antisymmetric magnetic coupling constant αas.

The invention relates to a method (100) for determining a ground state (1001) of a quantum system, comprising the steps of: providing (101) a hybrid variable component sub-algorithm and implementing (102) the hybrid variable component sub-algorithm (1010) on a hybrid computer platform comprising a classic computer and a quantum computer for implementing a quantum circuit (1011), in which the hybrid variable component sub-algorithm (1010) is implemented, wherein a gate parameter (1020) is determined (1025) on a classical computer by solving a differential equation comprising an equation matrix and an equation vector, and wherein a virtual time evolution of the gate parameter (1020) determined by solving the differential equation for a time step is determined (1026) by applying a Runge-Kutta method. The invention further relates to a hybrid computer platform, to a hybrid variable component sub-algorithm and to a use of the method for material simulation.

A frequency-tunable coupler (130) couples first and second quantum systems (110, 120), the coupler (130) and the second quantum system (120) being arranged so that tuning the coupler (130) to the second quantum system (120) forms a hybridized mode with a symmetric state and an asymmetric state, coupled to a waveguide (140) The coupler (130) is driven with an excitation-preserving transition signal to transfer a first excited state of the first quantum system (110) to the asymmetric state of the hybridized mode, thereby emitting a photon encoded with a first part of a quantum state into the waveguide at a first frequency. The first quantum system (110) is simultaneously driven with a non-excitation-preserving transition signal to transfer a second excited state of the first quantum system (110) to the symmetric state of the hybridized mode, thereby emitting a second photon encoded with a second part of the quantum state, at a second frequency.

The invention relates to a method for evaluating a measurement signal (5') emitted by an NV quantum system (4). The NV quantum system (4) is initialised using pulsed excitation light (13, 320) and is subjected to an alternating magnetic field (3; 310) which alternately assumes two different field states. The measurement signal (5') emitted by the NV quantum system (4) is detected and integrated over an integration window (331) that includes a signal time of a first light pulse (322) in order to obtain a signal value, and over an integration window (332) that includes a signal time of a second light pulse (322) in order to obtain a reference value, wherein the first and the second light pulses are two temporally offset light pulses of the excitation light (13; 320), wherein the first light pulse (322) is generated after the alternating magnetic field (3; 310) has assumed a first of the two field states, and wherein the second light pulse (322) is generated after the alternating magnetic field (3; 310) has assumed a second of the two field states. A measurement value is determined from the signal value and the reference value.

A quantum computing method includes determining an initial quantum state of a quantum system, and inputting the initial quantum state to a quantum circuit corresponding to the quantum system and obtaining a quantum state outputted by the quantum circuit, wherein the outputted quantum state is a quantum circuit generation state corresponding to the quantum system. The method further includes updating a quantum system parameter based on the outputted quantum circuit generation state. The quantum system parameter includes a quantum imaginary-time parameter. The method further includes updating a quantum circuit parameter of the quantum circuit according to the updated quantum system parameter to obtain an updated quantum system, and determining a final quantum state of the quantum system as a minimum eigenstate of the quantum system.

The invention discloses a quantum information feature extraction method, computer equipment and a computer readable storage medium. The method comprises the steps of obtaining quantum observation data of a quantum system; performing frequency domain conversion processing on the quantum observation data, and determining frequency domain characteristic data corresponding to the quantum observation data; according to the frequency domain feature data, target feature parameters are determined, and the target feature parameters are used for regulating and controlling the quantum system. Therefore, the frequency domain feature data can be obtained by performing frequency domain conversion processing on the quantum observation data, so that the target feature parameters are accurately obtained according to the frequency domain feature data, high-precision extraction of the target feature parameters is ensured, support is provided for accurate calibration of a quantum system, and automatic extraction of the quantum information feature data is realized. In addition, compared with a mode of judging the regulation and control parameter value of the quantum system only depending on experience, the implementation mode of the invention can eliminate subjective errors and improve the calibration precision of the quantum system.

The invention relates to a quantum system (1) for stabilizing Bose quantum bits, said system comprising: an instruction circuit (5) comprising three microwave sources (11, 13, 15), and a nonlinear superconducting quantum circuit (3) comprising a four-wave hybrid nonlinear element (7) and a resonant section (9), the quantum circuit (3) has a first mode having a first resonant frequency and a second mode having a second resonant frequency. The quantum circuit (3) is arranged to design a Hamiltonian H expressed as, by dissipation in the second mode, produce an effective dissipater that stabilizes the Bose quantum bits. To this end, the first microwave source (11) delivers frequency-equal radiation, the second microwave source (13) delivers frequency-equal radiation, and the third microwave source (15) delivers frequency-equal radiation to drive the second mode.

This application discloses a method and related apparatus for determining quantum state prediction values, relating to the field of quantum information technology. It includes: after determining the first and second quantum state data of the quantum system to be predicted, inputting these two types of data into a quantum system evolution predictor to obtain the third quantum state data. This application captures the time-varying second quantum state data through continuous weak measurements, solving the problem in traditional schemes where projective measurements disrupt the original evolution path of the quantum system, ensuring that the quantum system evolves according to the original path. Simultaneously, after capturing the second quantum state data closely related to spatiotemporal correlation noise through continuous weak measurements, a pre-trained time-series model is used, i.e., the quantum state evolution predictor learns the spatiotemporal correlation characteristics implicit in the second quantum state data, improving prediction accuracy in complex environments and enabling more accurate prediction of quantum state data during the evolution of the quantum system.

This invention relates to the field of traffic safety technology, specifically to an efficient simulation method for quantum systems based on parallel order reduction. The method includes the following steps: receiving the physical parameters of the quantum system and simulation requirements, whereby the physical parameters include electron mass, potential well size, and initial wave packet parameters; and the simulation requirements include simulation physical time and accuracy requirements. Based on the physical parameters, a time-dependent Schrödinger equation describing the dynamic behavior of the quantum system is established, and the Schrödinger equation is rearranged into matrix form using the Kronecker product. This invention utilizes Arnoldi to reduce the order of the matrix-form Schrödinger equation. By reducing the order, the large matrix in the original space is projected into a relatively small subspace, improving the efficiency of the simulation solution. The reduced-order Schrödinger equation is solved using a time-parallel algorithm. This approach overcomes the time step limitation imposed by the CFL condition, ensuring that a stable solution can be obtained with fewer time steps.

Systems and methods for performing fault tolerant quantum operations for the 4-legged cat code are provided. The quantum systems include an ancilla qubit dispersively coupled to a first logical qubit, and the quantum system may be operated at least in part by: generating and applying a first drive waveform to the ancilla qubit, the first drive waveform comprising a first comb of 7t-pulses having selective frequencies corresponding to a first selection of even and odd cavity resonance frequencies of the first logical qubit; and reading out a state of the ancilla qubit.

Systems, methods, and quantum circuits for estimating an expectation value of an observable of a physical quantum system. A plurality of qubits is received, including inner and outer register qubits and state simulation qubits prepared in a reference eigenstate of a Hermitian operator having a reference eigenvalue. A first unitary operation is performed that receives the inner register and state simulation qubits as input and outputs phase information. The phase information is related to the reference eigenvalue and a plurality of eigenvalues of a first operator corresponding to the observable. The outer phase register qubits are measured to obtain classical measurement results that are used to determine an expectation value of the observable for the reference state.

The invention provides a quantum system data processing method based on light quantum and a light quantum computer, and the method comprises the steps: obtaining an ordinary differential equation and the attribute information of the ordinary differential equation; according to the frequency spectrum number of the ordinary differential equation and the attribute information of the ordinary differential equation, constructing an initial light quantum circuit corresponding to the ordinary differential equation; measuring the initial light quantum circuit, and determining a target function corresponding to the initial light quantum circuit according to a measurement result; loss information of the target function is determined, whether the initial light quantum circuit is applied or not is determined according to the loss information, and if yes, the initial light quantum circuit serves as a target light quantum circuit; and performing operation on input data of the quantum system based on the target light quantum line. According to the method, the light quantum circuit expression capability can be greatly improved, and high-precision solving of the ordinary differential equation is realized.

Systems and methods for performing fault-tolerant quantum operations for cat code are provided. A quantum system includes an ancilla qubit dispersively coupled to a first logical qubit, and the quantum system can be operated at least in part by: generating a first drive waveform and applying the first drive waveform to the ancilla qubit, the first drive waveform including a first comb of pi pulses having selective frequencies corresponding to a first selected pair of even and odd cavity resonance frequencies of the first logical qubit; and reading out a state of the ancilla qubit.

A computer-implemented system and method for determining collapse states in quantum and probabilistic systems using wave-interference-based computation are disclosed. The system models collapse as a deterministic process arising from interaction between a system wavefunction and one or more observer or environmental wavefunctions. A modified Schrödinger-type formulation is used to compute a real-valued collapse intensity based on amplitude coupling and phase alignment between interacting wavefunctions. The system further aggregates the collapse intensity over a spatial domain to generate a scalar collapse measure, which is compared against a predefined threshold to determine collapse conditions. The invention enables simulation, prediction, and control of collapse behavior across quantum systems, probabilistic computation, and collapse-driven decision architectures.

The invention provides a method and a quantum characterisation unit that (i) prepares the quantum system in at least two (preferably three or more) distinct dynamical configurations, each describable by its own stochastic master equation (SME) but sharing a subset of physical parameters; (ii) records continuous detector signals, bins or filters them, and computes low order correlation functions (one, two, three point, optionally higher order) from repeated measurements; and (iii) jointly fits simulated correlation functions — generated directly from the SME without trajectory sampling — to the experimentally obtained ones, using a least squares (or similar) optimisation to assign values to the shared parameters. The method exploits the fact that different configurations break parameter degeneracies that would be hidden in a single configuration.

The invention discloses a quantum system and method for accurately controlling quantum state localization and phase change, and a reliable technical means of actively inducing extended state reentry in a local phase breaks through the traditional limitation of'local phase irreversibility ', and provides possibility for'wake-up' and reset of quantum information. It is proved that the capability of inducing reentry is insensitive to the mobility edge, so that the technology has high robustness and universality and is suitable for wider system conditions; non-Hermite is introduced as new regulation, quantitative and fine regulation of reentry critical conditions is realized, and a direct relation between localization and PT symmetry is established; a set of comprehensive diagnosis scheme is provided, a complex phase structure, especially a mixed phase which is difficult to accurately judge by a traditional method, can be clearly and correctly recognized, and the accuracy of experimental observation and phase diagram construction is ensured; and finally, a multifunctional, high-sensitivity and strong-robustness quantum state controller is realized.