47 results about "Ground state" patented technology

The invention relates to the technical field of quantum computing, and provides a polariton quantum computing simulation method and related device.The method comprises the steps that parameterized quantum circuits are generated based on micromodels used for describing polaritons for all to-be-computed excitation states respectively, and the parameterized quantum circuits are generated based on initial Hamiltonian of polaritons in a ground state; the target Hamiltonian amount of the polariton in the current excitation state is obtained, then the value of each parameter is adjusted at least once, and the target energy of the corresponding excitation state is obtained. In the primary adjustment process, parameter updating is carried out on the quantum circuit, a reference quantum state of the corresponding excitation state is obtained by utilizing the updated quantum circuit, reference energy of the corresponding excitation state is obtained based on the reference quantum state and in combination with the target Hamiltonian, and then when a set convergence condition is met, the target Hamiltonian is obtained. And taking the reference energy as target energy of the corresponding excited state. The polaritons are simulated through the quantum computer, and the simulation efficiency is improved.

The invention discloses a quantum phase-locked detection method based on entanglement enhancement, and the method comprises the steps: encoding quantum bits in a ground state and an excited state, and preparing the quantum bits into an initialized quantum state; loading a periodic multi-pulse sequence to act on the quantum bits; and loading a carrier pulse resonating with the ground state and the excited state, detecting the final quantum state of the quantum bit, and comparing curves of each component of the measurement density matrix and the theoretical density matrix changing along with the pulse time interval of the periodic multi-pulse sequence to obtain the half cycle and the amplitude of the sine wave to be measured. According to the method, measurement noise under the condition that the rotation angle and the detuning error exist can be effectively restrained, high measurement precision is kept under the condition that the rotation angle and the detuning error exist, and the robustness enables the method to be more reliable in practical application.

The application discloses a kind of based on ensemble rare earth ions double quantum bit controlled gate construction method, it is related to quantum control technical field, it includes to double quantum bit frequency site selection, and respectively as control bit, target bit;Utilize the blocking effect generated by the dipole-dipole interaction between double quantum bits to construct controlled gate, including: to control bit apply light pulse driving control bit is from ground state transition to excited state;To target bit apply single quantum gate to drive its evolution, and apply compensation pulse;To control bit apply light pulse driving control bit from excited state de-excitation to ground state.The application utilizes the interaction of the light pulse and quantum system medium that can be optimized to produce arbitrary geometric quantum logic gate on target quantum bit, and simultaneously by using the blocking effect caused by dipole-dipole interaction, the evolution of target bit quantum bit can be constrained by control bit.

The application discloses a quantum phase-locked detection method based on entanglement enhancement, encodes quantum bits in a ground state and an excited state, and prepares the quantum bits as initial quantum states; a periodic multi-pulse sequence is loaded on the quantum bits; a carrier wave pulse resonating with the ground state and the excited state is loaded; a final quantum state of the quantum bits is detected; curves of each component of a measured density matrix and a theoretical density matrix changing with a pulse time interval of the periodic multi-pulse sequence are compared; and a half period and an amplitude of a to-be-measured sinusoidal wave are obtained. The application can effectively suppress measurement noise under the condition of existing rotation angles and detuning errors, and can maintain high measurement precision under the condition of existing rotation angles and detuning errors. The robustness makes the application more reliable in practical application.

This invention provides a method and apparatus for determining the ground state energy of a target molecular system. The method includes: determining a first Hamiltonian of the target molecular system using the Born-Oppenheimer approximation; determining a first correction term using a preset perturbation expansion based on a preset mass ratio parameter of electrons to atomic nuclei in the target molecular system and the first Hamiltonian; applying the first correction term to the first Hamiltonian to obtain a second Hamiltonian; and determining the ground state energy corresponding to the second Hamiltonian based on the second Hamiltonian and a preset variable quantum circuit.

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.

Systems and methods are disclosed for determining interaction parameters for multiple particles, each particle having a ground state, an excited state, and one or more intermediate states The multiple particles are configured to interact with a plurality of electromagnetic fields associated with a (different) transition between two states. The method comprises performing a spectroscopy measurement, measuring an effective Rabi frequency Ωeff, measuring a single-photon Ramsey frequency ΩR i , and determining the interaction parameters based on the measured effective detuning δ eff, the measured effective Rabi frequency Ωeff, and the measured single-photon Ramsey frequencies ΩR i . The interaction parameters may be determined for each of the multiple particles. The interaction parameters may comprise a single-photon Rabi frequency Ω i for each electromagnetic field, which may be used to align the electromagnetic fields with respect to the particles.

The invention relates to the cross technical field of quantum calculation and quantum chemistry, and particularly discloses a variable component subscript solicitation method and device based on physical symmetry, a medium and equipment, the method comprises the following steps: obtaining target system information, the target system information comprises Hamiltonian, electron number, orbit energy distribution and symmetry of a target system; reducing the Hamiltonian based on the electron number and the orbit energy distribution, and converting the reduced Hamiltonian from a Fermi operator form to a Fouli operator form to obtain a Fouli Hamiltonian; determining a variable component sub-line based on the symmetry; and solving the Follicle Hamiltonian quantity based on the variable component sub-line to obtain the ground state energy of the target system. The method solves the problem that the current quantum calculation bit number is difficult to adapt to a large chemical system.

A method for measuring a preferably static magnetic field is claimed, comprising the following steps in this order: i) Excitation of a valence electron of one or more alkali atoms (2) from a ground state to an initiation state in a manifold with principal quantum number n; ii) Application of a ½ control pulse to generate a superposition, preferably a uniformly distributed superposition, between the initiation state and a control state; iii) Application of a sequence of circulation pulses and one or more control pulses, preferably with specific time intervals, to shift the valence electron within the manifold of the initiation state; iv) Application of a further ½ control pulse for coherent mixing of the populations in the initiation state and control state; v) Measurement of the state of the valence electron, and preferably calculation of the magnetic field;

This invention discloses a molecular dynamics calculation method and system based on quantum simulation. The method first applies a discrete quantum Fourier transform to the atomic coordinates of the molecular system, mapping the original plane wave basis to a system containing only O(N) atoms. 2 The invention constructs a plane-wave bibasic quantum mechanics equation; then, it constructs and solves the electronic structure Hamiltonian on a quantum computer to obtain the ground state energy. This quantum energy is combined with the classical empirical potential energy according to predetermined weighting coefficients to calculate the total synthesized energy, from which the atomic forces are determined. The integration time step is then adaptively adjusted based on a comparison of the quantum energy change between consecutive time steps with a preset threshold. This adaptive mechanism shortens the time step to ensure accuracy when quantum effects are significant, and lengthens the step to improve efficiency when changes are gradual. This invention significantly reduces Hamiltonian complexity, balancing quantum accuracy and classical efficiency, and is applicable to various fields such as drug screening, materials design, and catalytic reaction simulation.

The invention provides a multi-component magnetic alloy Curie temperature calculation method and device, a medium and equipment, and the method comprises the steps: defining to-be-calculated alloy components, and generating an input file needed by an EMTO calculation program based on preset calculation parameters; traversing each alloy component, and generating corresponding KGRN and KFCD input files in combination with preset crystal structure types and magnetic configuration configurations; an EMTO calculation program is called, calculation tasks are executed in batches based on the input file, and the calculation tasks comprise KGRN and KFCD tasks which are executed in sequence; automatically extracting state equation data based on an output result of the calculation task; batch fitting is carried out based on the extracted state equation data so as to predict ferromagnetic state ground state total energy and paramagnetic state ground state total energy; and based on the total energy of the ferromagnetic ground state and the total energy of the paramagnetic ground state, which are obtained by fitting, calculating the Curie temperature by adopting an average field theoretical formula. The method greatly reduces the time components of experiment trial and error and saves the capital cost.

The application discloses a kind of method, device and medium for calculating the energy of target system, method includes: first determine the Hartree Fock state of fermion form of target system, then construct quantum phase estimation circuit, generate the control pulse of quantum logic gate in quantum phase estimation circuit, and the control pulse is acted on quantum bit in quantum phase estimation circuit, so that specified quantum bit is evolved from Hartree Fock state to target quantum state, finally, according to Hartree Fock state and target quantum state, the ground state energy of the target system is calculated, it is constructed by quantum phase estimation circuit that can be used for current quantum computing hardware equipment, for the realization of quantum chemistry simulation calculation target system energy provides support, improve computing speed and calculation accuracy, promote the simulation calculation of target system ground state energy.

The invention discloses a double-quantum-bit controlled gate construction method based on ensemble rare earth ions, and relates to the technical field of quantum control, and the method comprises the steps: carrying out the site selection of double-quantum-bit frequency, and taking the double-quantum-bit frequency as a control bit and a target bit; a controlled gate is constructed by using a blocking effect generated by dipole-dipole interaction between double quantum bits. The method comprises the following steps: applying an optical pulse to a control bit to drive the control bit to transition from a ground state to an excited state; applying a single quantum gate to the target bit to drive the target bit to evolve, and applying a compensation pulse; and applying an optical pulse to the control bit to drive the control bit to be de-excited from the excited state to the ground state. According to the invention, any geometric quantum logic gate is generated on a target quantum bit by utilizing the interaction of optimizable light pulses and a quantum system medium, and meanwhile, the evolution of the target bit quantum bit can be restrained by a control bit by utilizing a blocking effect caused by dipole-dipole interaction.

The application provides a Curie temperature calculation method, device, medium and equipment of a multi-component magnetic alloy, which comprises the following steps: defining alloy components to be calculated, and generating input files required by an EMTO calculation program based on preset calculation parameters; traversing each alloy component, and generating corresponding KGRN and KFCD input files in combination with preset crystal structure types and magnetic configuration configurations; calling the EMTO calculation program, performing a calculation task in batches based on the input files, including sequentially performing KGRN and KFCD tasks; automatically extracting state equation data based on the output results of the calculation task; performing batch fitting based on the extracted state equation data to predict ferromagnetic state ground state total energy and paramagnetic state ground state total energy; and calculating the Curie temperature by using an average field theory formula based on the ferromagnetic state ground state total energy and the paramagnetic state ground state total energy obtained by fitting. The method greatly reduces the time component of experimental trial and error and saves the cost.

A technique is provided for cooling generic many-body quantum systems of unknown Hamiltonians to their ground states with a very high fidelity. The technique works by switching on a strong field and applying a sequence of projective measurements and RF pulses to polarize the system along the direction of the external field before we adiabatically switch the field off. The evolution of the system towards its ground state is governed by the quantum adiabatic theorem. We numerically simulate the proposed technique for quantum spin chains with long and short range interactions.

Selective frequency dissipation is implemented that enables cooling of energy gap protected qubits such that excited energy states resulting from heating or other undesired processes are returned to a lower excited energy state or a ground state manifold, thus reducing the probability of errors. Also, the selective frequency dissipation inhibits leakage from the energy gap protected qubits when in the ground state. Additionally or alternatively, Hamiltonian engineering by inducing parity rotations is implemented to decouple the wells of the energy gap protected qubit to further reduce errors when leakage does happen.

This invention discloses a method for designing induced magnetic skyrmions based on geometric structures, specifically including: constructing geometric structures such as ripples, folds, and depressions in two-dimensional magnetic materials to break the central inversion symmetry and induce Dzyaloshinskii-Moriya (DM) interactions, providing conditions for designing topological magnetic structures such as magnetic skyrmions; presenting detailed magnetic parameters of the studied system through first-principles calculations, including Heisenberg exchange coupling, DM interactions, and magnetic anisotropy; and solving for the magnetic ground state under various magnetic interaction competitions based on micromagnetic simulations, including topological magnetic structures such as magnetic skyrmions.

A system includes a processor that executes computer executable components stored in a memory. The computer executable components can comprise can comprise a reference component that selects reference state and applies time evolution with respect to a Hamiltonian for different times to prepare Krylov basis states on a quantum device; a base component that prepares the Krylov basis states to obtain a fixed number of samples by sampling from the prepared basis states to classically represent the original Hamiltonian; and a representation component that classically represents the original Hamiltonian in subspace generated by the fixed number of samples to diagonalize the Hamiltonian in a bitstring subspace to obtain an approximation of ground state energy of the original Hamiltonian.

The present disclosure relates to a system for performing a quantum manipulation protocol, e.g., a quantum computing algorithm, the system comprising: a trapping laser system for trapping neutral atoms in an optical trap array inside a vacuum chamber operated at a trapping wavelength λtr, wherein each neutral atom comprises a ground state |1S0>, a first metastable excited state |3P0> and a second metastable excited state |3P2>. The system further comprises a state manipulation laser system for generating laser radiation for coupling, via a phase-coherent multi-photon transition, the ground state |1S0> to the first metastable excited state |3P0> and / or to the second metastable excited state |3P2> as well as a magnetic field system for generating a magnetic field Bext at a location of the optical trap array inducing a Zeeman splitting for magnetic substates of the second metastable excited state |3P2>. The system further comprises a control system for controlling the laser radiation generated by the laser system to coherently modify a quantum state of the plurality of neutral atoms based on the quantum manipulation protocol and a quantum state readout system for determining the quantum state of at least a subset of the plurality of neural atoms based on the quantum manipulation protocol. According to some aspects, a direction of the magnetic field Bext with respect to a polarization direction of the optical trap array is selected such as to render the optical trap array operated at the trapping wavelength λtr a magic- wavelength optical trap for the second metastable excited state |3P2> and the first metastable excited state |3P0> and / or for the second metastable excited state |3P2> and the ground state |1S0> or both. A state-selective detection scheme as well as related devices and methods are also disclosed.

The invention relates to a method for determining an error-corrected desired value of an observable measurement of a quantum system by means of a classical computer, comprising the following steps: providing a first desired value of the observable measurement dependent on a first distance metric, wherein the first distance metric is indicative of a spatial separation between the first set of qubits and the second set of qubits; providing at least one second desired value, which is observably measured and depends on the second distance metric; determining an adapted fitting function, comprising the steps of: 0 providing a fitting function, the fitting function comprising at least one fitting parameter, and the fitting function being dependent on a distance metric; 0, fitting a fitting parameter of the fitting function to the first expected value and the second expected value; determining an error-corrected desired value of the observable measurement by evaluating the adapted fitting function for the distance metric using a value greater than the first distance metric and the second distance metric; an error-corrected desired value is provided.

The application relates to the technical field of strong-field high-harmonic generation, and particularly discloses a double-electron quantum correlation quantitative method and system based on Bohm mechanics, which comprises the following steps: establishing a time-dependent Schrodinger equation containing an external laser field, obtaining a system ground state wave function and generating N pairs of Bohm particles initial coordinates, and performing time evolution on the wave function; according to the evolved wave function, the accurate velocity field and the accurate motion trajectory of each Bohm particle are calculated; based on the marginal probability density and the marginal probability flow density, the marginal velocity field not containing instantaneous quantum correlation effects is constructed, and the corresponding correlation-free reference trajectory is generated; the accurate trajectory is compared with the reference trajectory, and the correlation model of the correlation quantum potential and the high-harmonic radiation intensity is established. Through comparison of the accurate Bohm trajectory and the correlation-free reference trajectory constructed based on the marginal velocity field, the quantum correlation effects in a strong-field double-electron system are quantitatively separated and visually output.

This invention discloses a debugging method and apparatus for an atomic gravimeter, and the atomic gravimeter itself, relating to the field of atomic gravimeter technology. This invention can control the Raman light source to change the frequency difference between two Raman beams, causing the two beams to interact with atomic groups in a vacuum chamber. A fluorescence collection device can detect the ground state energy level population of atoms in the vacuum chamber. The main unit can plot a Raman spectrum showing the probability of an atom being in the target ground state as a function of the frequency difference, based on the ground state energy level population. By determining whether the Raman spectrum meets the preset conditions corresponding to the target polarization state, the polarization state of the Raman light in the atomic gravimeter can be judged to be in the desired state.

A non-transitory computer-readable storage medium storing a solution search program that causes at least one computer to execute a process, the process includes reducing, when searching for a ground state of the Ising model that represents a problem by obtaining a state change of the Ising model, a strength of a magnetic field applied to the Ising model according to a first annealing schedule from an initial state of the Ising model; and reducing, after a quantum phase transition occurs in the Ising model, the strength of the magnetic field according to a second annealing schedule.

The application discloses a kind of method and system for measuring atomic beam flow velocity, the method excites the atom in ground state in the first resonance laser in the second resonance action area, and the first resonance laser is the laser that frequency is locked on the first resonance transition spectral line of atom;After the intensity of detected fluorescent signal reaches the first stable amplitude value, the atom in ground state in the first resonance action area is excited by the second resonance laser at the first time point, and the second time point when fluorescent signal intensity starts to weaken is determined, the second resonance laser is the laser that frequency is locked on the second resonance transition spectral line of atom, and the excited state energy level lifetime of the second resonance transition spectral line of atom is longer than the first resonance transition spectral line;According to the determined atomic transit displacement and atomic transit time, the velocity information of atomic beam flow is determined.The application solves the problem that the previous experiment calculates the velocity of atomic beam flow, and the measurement precision is poor, the reliability is low, and the practical measurement verification is lacked.

The application relates to the technical field of quantum computing, and provides a quantum phase transition point positioning method and device. The method comprises the following steps: initializing a first line to an eigenstate of a first initial Hamiltonian, evolving the first line, making the first line evolve to an eigenstate of a target Hamiltonian and then returning to the eigenstate of the first initial Hamiltonian, and measuring the evolution energy error of the first line; initializing a second line to an eigenstate of a second initial Hamiltonian, evolving the second line, making the first line evolve to the eigenstate of the target Hamiltonian and then returning to the eigenstate of the second initial Hamiltonian, and measuring the evolution energy error of the second line; finding the Hamiltonian parameter corresponding to the same evolution energy error of the first line and the second line, that is, the phase transition point of the quantum computing problem. The application can accurately position the quantum critical point without accurately obtaining the ground state data of the quantum critical point, and only needs a small amount of quantum resources.

An information processing apparatus iterates a process of updating a value of a coefficient in a third equation and a process of searching for a ground state of a many-electron system. The third equation is obtained by adding a term, which is a product of a second equation relating to the number of electrons in the many-electron system and the coefficient, to a first equation for computing a physical quantity of the many-electron system. The search process employs a variational quantum eigensolver method and searches for the ground state of the many-electron system by setting, in the (k+1)th search process, a final state of the many-electron system obtained in one of the first to k-th search processes as an initial state, and then changing the quantum state of the many-electron system from the initial state such that the expected value of the third equation is reduced.

The application discloses a kind of machine learning methods based on physical observation analog quantum computing system error, belong to involve quantum computing field, including: step 1: from the one-dimensional p wave topological superconductor of belonging to BDI symmetry class constructs minimum extensible 2-MZM island;Step 2: according to the minimum extensible 2-MZM island established, the ground state hamiltonian of island is obtained;Step 3: in minimum extensible 2-MZM island, the hamiltonian of the interaction of boson heat bath is obtained by introducing boson heat bath interaction;Step 4: the state of minimum extensible 2-MZM island is described with time t changes by Pauli master equation;Step 5: the probability of different errors is obtained by using standard dwell time monte carlo algorithm to simulate Pauli master equation;Step 6: the final state probability of the i th MC event is predicted on minimum extensible 2-MZM island by training machine learning model through monte carlo event.This method can effectively predict error probability in the minimum extensible range, significantly improve efficiency.

According to an embodiment, an arrangement for quantum computing comprises: a first quantum system having a plurality of Fock quantum states comprising at least a zero-photon state, a one-photon state, and a two-photon state; and a second quantum system coupled to the first quantum system and comprising at least a ground state and one or more excited states and is configured to, via the coupling, cause at least one of the one or more excited states to hybridize with the two-photon state of the first quantum system causing the two-photon state to split into a first hybridized state and a second hybridized state, wherein an energy difference between the one-photon state and the first hybridized state is non-equal to an energy difference between the zero-photon state and the one-photon state and an energy difference between the one-photon state and the second hybridized state is non-equal to the energy difference between the zero-photon state and the one-photon state.

The application discloses a multi-physical field coupling and impedance spectrum analysis flame detector nondestructive testing method and system, and relates to the technical field of helicopter flame detector nondestructive testing.The temperature field and the electromagnetic field are coupled to replace light, so that a simulation environment of fire radiation effect is provided for the flame detector, and the photochemical reaction of the photoelectric material caused by light is avoided; the error is eliminated through wide frequency scanning and the four-electrode method, the impedance spectrum is obtained through inversion calculation, and the physical parameters are obtained through deconstruction, so that the problem that the continuous relaxation process information contained in the wide frequency data is lost in traditional impedance analysis is avoided; the classical physical parameters of the sensor fault are mapped into the Hamiltonian of the quantum system, the fault is sensed by solving the ground state, and the defects that the classical machine learning is easy to fall into local optimization when processing high-dimensional, nonlinear and strongly correlated fault features, and the model is poor in interpretability.

Methods and apparatus for generating quantum entanglement links between matter qubits in a quantum communication system A matter qubit may be arranged in an optical cavity configured to stimulate photon emission and an energy level transition from an excited state energy level to a third ground state energy level. The matter qubit may be initialised in a superposition of a first ground state energy level and a second ground state energy level. The matter qubit may be exposed to a first instance of an excitation field configured to excite the matter qubit from the second ground state energy level to the excited state energy level. The matter qubit may be subjecting to a control field configured to cause an energy level transition from the first ground state energy level to the second ground state energy level before being exposed to a second instance of the excitation field.