76 results about "Double quantum" patented technology

The invention discloses an image classification method based on an extensible quantum convolutional neural network, and relates to the technical field of image classification, and the method comprises the steps: carrying out the preprocessing of to-be-classified image data, and then carrying out the slicing processing; converting the slice data into quantum state information through angle coding; a quantum system is constructed, the quantum system comprises a quantum feature extraction part and a quantum classification measurement part, the quantum feature extraction part comprises a quantum variational circuit model with a quantum convolutional layer, and the model can perform feature extraction on quantum state information by using alternating single quantum bit gates and double quantum bit gates; training a quantum variational circuit model by using a part of quantum state information; and inputting the other part of quantum state information into the trained quantum variational circuit model, and measuring the output quantum state of the quantum variational circuit model. According to the method, the problems that traditional deep learning is high in computing resource demand, limited in quantum computer scale and the like are solved, and a novel and practical method is provided for efficient image classification.

The invention discloses an underwater magnetic field measuring device based on a diamond NV color center. The underwater magnetic field measuring device comprises a diamond NV color center module, an incident laser excitation module, a multi-path optical coupling module, a microwave excitation module, a fluorescence acquisition and photoelectric conversion module, a signal processing and control module and a magnetic field module, the multi-path optical coupling module is used for dividing an optical fiber into multiple paths and collecting fluorescence generated by the diamond block; the microwave excitation module is used for switching between two single-quantum resonance frequencies to drive an NV color center to realize double-quantum DQ reading; and the signal processing and control module comprises an FPGA (Field Programmable Gate Array) processing unit of a field programmable logic array chip. According to the invention, a dual-quantum DQ working point of a diamond NV color center is used as a measurement channel, common-mode influence of D is removed through differential measurement, the problem of D drift caused by temperature drift, stress and material aging is physically and obviously inhibited, and the device can still realize ultrahigh-sensitivity measurement in a complex underwater environment.

Photonic controlled-phase gates that include a dipole emitter chirally coupled to a plurality of photonic qubit pairs in a waveguide are disclosed herein. Each photonic qubit pair includes a two-qubit state |xy, wherein the two-qubit state |xy comprises a combination of single-qubit states |0 and |1, and may be |00, |01, |10, and |11. The dipole emitter is configured to interact with the single-qubit state |0 to impose a π phase shift, and the dipole emitter interacts with states |00, |01, and |10 to impose the π phase shift.

To shorten the computation time for an expected value of a ground state energy of a molecule.SOLUTION: An information processing device 10 creates multiple quantum bit pairs, each of which is formed by combining a first quantum bit and a second quantum bit. The first quantum bit corresponds to a first orbital in which an electron is present in the initial configuration. The second quantum bit corresponds to a second orbital in which an electron is not present in the initial configuration. The information processing device 10 generates a quantum circuit 3 which applies two-qubit gates 4a to 4j to at least a part of the multiple quantum bit pairs. The two-qubit gates 4a to 4j are quantum gates which generate a superposition state according to a parameter value between a first state in which the states of the first and second quantum bits are not swapped and a second state in which the states are swapped. An expected value of a ground state energy of a molecule is acquired by causing a quantum computer 1 to repeatedly execute the quantum circuit 3.SELECTED DRAWING: Figure 1

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.

This invention discloses a method and device structure for improving the electrical transport properties of etched graphene quantum dots, belonging to the field of low-temperature transport testing technology. The method includes the following steps: fabricating etched graphene quantum dot devices; performing preliminary electrical transport characterization by cooling; and undergoing several cycles of "sample electrode grounding protection – heating to above 200K or room temperature – cooling again – electrical transport characterization" to improve the electrical transport properties of the device, enabling subsequent observation and manipulation of the quantum dot's fine charge stability map. The optimized method of this invention, through several heating and cooling thermal cycles, successfully adjusts the coulomb blocking region of the graphene quantum dots from hundreds of volts towards zero, facilitating the application of a gate voltage. Furthermore, the charge stability map of the two quantum dots is significantly optimized and improved, greatly increasing the yield of etched graphene quantum dot devices. In addition, the optimized method of this invention is simple to operate and has significant effects, making it suitable for widespread application.

An information processing apparatus creates qubit pairs, each being formed by combining first and second qubits. A first qubit corresponds to a first orbital on which an electron is present in an initial arrangement. A second qubit corresponds to a second orbital on which no electron is present in the initial arrangement. The apparatus generates a quantum circuit that applies two-qubit gates to at least some of the qubit pairs. Each two-qubit gate generates, based on the value of a parameter, a superposition state of a first state in which the states of the first and second qubits are not switched and a second state in which these states are switched. The apparatus acquires an energy expectation value in the ground state of the molecule by causing a quantum computer to iteratively execute the quantum circuit.

Methods, systems, and apparatus for benchmarking quantum computing hardware. In one aspect, a method includes defining an initial circuit configured to operate on an array of qubits, wherein the initial circuit includes multiple instances of a two-qubit gate, wherein each instance of the two-qubit gate performs the same operation on a corresponding adjacent pair of qubits in the array; partitioning the initial circuit into multiple layers, wherein the instances of the two-qubit gate in the corresponding layer can be implemented in parallel; for each layer in the multiple layers: constructing a benchmarking circuit for the layer, wherein each benchmarking circuit of the layer includes one or more cycles of quantum gates, each cycle including: a layer of instances of the two-qubit gate and multiple single-qubit gates; implementing the constructed benchmarking circuit to obtain experimental benchmarking data; and adjusting control parameters of a control model using the experimental benchmarking data.

The present disclosure relates to an apparatus and method for quantum computing using a plurality of neutral atoms in an optical trap array wherein a first internal state of the neutral atoms is used as a qubit ground state 0gt; the second internal state is used as a quantum bit excitation state 1gt; . According to the present disclosure, a local single qubit gate operation can be performed on a qubit, comprising locally and selectively irradiating with a qubit addressing laser at a first qubit addressing laser frequency, which is prepared as a qubit ground state 0gt; and a quantum bit excited state 1gt; a superposition state sgt; the quantum bit is used for causing a quantum bit ground state 0gt; and a quantum bit excited state 1gt; and the differential stark displacement is realized. Furthermore, a local dual qubit gate operation may be performed on the pair of qubits, including locally and selectively irradiating with a qubit addressing laser at a second qubit addressing laser frequency prepared as a qubit ground state 0gt; a pair of qubits for a third internal state cgt, preferably via neutral atoms; coupling the quantum bit pair to a Rydberg state rgt of a neutral atom; a third internal state cgt; the method can be used as a quantum bit ground state 0gt; a Rydberg state rgt is obtained; and the intermediate state of two-photon transition is realized.

A method is provided, including: applying a magnetic field according to a two-qubit gate operation performed with a quantum device; transmitting a voltage signal to a gate structure, arranged above first and second quantum dots in the quantum device, to generate a coupling signal that includes a first sine squared wave; and performing, by the magnetic field and the coupling signal, the two-qubit gate operation to the first and second qubits in the first and second quantum dots.

Techniques are provided for mediating interactions (e.g., long range interactions) between quantum bits to facilitate quantum computing operations such as two-qubit gate operations. A device comprises a first quantum bit, a second quantum bit, and a coupling bus connecting the first quantum bit and the second quantum bit. The coupling bus comprises a plurality of transmission line resonators which are coupled in series, and at least one tunable inductive coupler to control a coupling between a first transmission line resonator and a second transmission line resonator of the plurality of transmission line resonators.

The invention belongs to the technical field of organic field effect transistors, and particularly relates to a high-mobility field effect transistor based on an organic double-quantum well structure and a preparation method of the high-mobility field effect transistor. The high-mobility field effect transistor comprises a grid electrode, an insulating layer, an organic semiconductor layer, a source electrode and a drain electrode, the insulating layer is located between the grid electrode and the organic semiconductor layer, an OTS modification layer is arranged between the insulating layer and the organic semiconductor layer, and the organic semiconductor layer is composed of a C8-BTBT layer / (Pentaene layer / C8-BTBT layer) n and n = 2 in the direction from the grid electrode to the source electrode and the drain electrode. According to the organic double-quantum well composed of C8-BTBT and pentacene, a potential well is formed by alternating different energy gap materials, carriers are limited in a narrow energy band region, scattering is reduced, directional transportation is promoted, and the mobility of the transistor is greatly improved.

The embodiment of the invention provides a frequency determination method and device, electronic equipment and a storage medium. According to the scheme, the method comprises the following steps: obtaining a first corresponding relation between coupler frequencies and leakage rates according to operation of at least one resonance type double-quantum logic gate on a first quantum bit and a second quantum bit in a target system under different coupler frequencies; based on the first corresponding relation, the coupler frequency corresponding to the lowest leakage rate is selected as the target frequency, and the target frequency is the frequency of a control signal applied to the adjustable coupler when the first quantum bit and the second quantum bit execute the resonance type double-quantum logic gate operation. Through the technical scheme provided by the embodiment of the invention, the frequency of the control signal applied to the adjustable coupler during the execution period of the resonance type double-quantum logic gate can be determined, so that an observer error is effectively inhibited, and the fidelity of quantum calculation is improved.

This invention discloses a highly self-assembled dual quantum dot / graphene heterojunction broadband memristor, its fabrication method, and its applications, belonging to the field of inorganic semiconductor technology. The method includes the following steps: mixing highly self-assembled cerium oxide quantum dot ink and PbS quantum dot ink with a graphene dispersion and stirring until homogeneous to form a uniformly loaded quantum dot / graphene dispersion; then using the quantum dot / graphene dispersion to construct a dual quantum dot / graphene heterojunction film on a silicon wafer surface, thus obtaining the dual quantum dot / graphene heterojunction broadband memristor. This invention overcomes the inherent limitations of the photoresponse range of single materials, achieving broadband optoelectronic memristor behavior in the ultraviolet to near-infrared bands. Simultaneously, the memristor of this invention exhibits rich synaptic plasticity under light pulse modulation, providing core support for constructing a novel integrated optoelectronic system for broadband sensing, storage, and processing. It possesses strong technical adaptability and industrialization prospects in cutting-edge fields such as bionic vision, optical neural networks, and intelligent sensing.

The invention discloses a method for obtaining pure spin thermoelectric force by irradiating T-type quantum dots with a light field, which comprises the following steps of: coupling two semiconductor quantum dots into a T-type double-quantum-dot structure, applying different temperature fields to electrodes on two sides connected with the quantum dots, and if a magnetic field is applied to the quantum dots, judging whether the quantum dots are in a spin state or not. According to the quantum dot structure, the coupling strength between the quantum dots can be related to the spin degree of freedom, so that when electrons in different spin directions flow through the quantum dot structure, different interference effects can be generated, peaks of spin upward thermoelectric force and spin downward thermoelectric force are separated in the quantum dot energy space, and pure spin thermoelectric force is obtained. The self-spinning thermoelectric force of the T-shaped double-quantum-dot structure is further enhanced by further adjusting the light field, and finally large pure self-spinning thermoelectric force is obtained. According to the method, a basis is provided for designing a quick-response, efficient and low-energy-consumption thermoelectric device, the effect of the method is superior to that of traditional charge thermoelectric potential, and the limitation of low thermoelectric efficiency is broken through.

This application discloses a method and apparatus for constructing a quantum entangled logic gate. The method involves performing preset operations on the spin-related shift of each phonon mode of the ions in the segment and the phase of each pair of accumulated two-qubits between segments to obtain a target correlation function. This target correlation function is then converted into a target function containing a preset vector. The introduced preset vector improves the computational speed of the phase-modulated quantum entangled logic gate. After solving for the local optimal solution of the target function, the logic gate is constructed based on the fidelity of the logic gate corresponding to the local optimal solution. This ensures that the constructed logic gate meets the fidelity requirements, thus realizing a quantum entangled logic gate applicable to large-scale ion arrays.

A gate sequence for performing quantum calculations may be generated by replacing an AshN gate with a particular dual qubit gate. The gate sequence may be generated by a classical computing system. The gate sequence generation process may include identifying, in a gate sequence, a dual qubit gate to be applied to two qubits of a quantum computing system. The dual qubit gate may be associated with Weyl coordinates x, y, and z. By utilizing the characteristics of the two qubits and Weyl coordinates, an AshN gate which is locally equivalent to the double-qubit gate can be generated. The AshN gate may be included in a gate sequence in place of the identified dual qubit gate. The gate sequence may then be applied to a quantum computing system to perform quantum computing.

To relax a quantum error in a quantum circuit using a non-Clifford gate.SOLUTION: The information processor 10 generates second quantum-bit circuits 3a, 3c,. by replacing the first two quantum-bit gates 4a to 7a in the first quantum-bit circuit 3 with a first equivalent circuit 7 including a second two quantum-bit gate 4b that performs a gate operation of phase-rotation by a first rotation angle. The information processor 10 replaces the first 2-qubit gates 3a to 3c in the first circuit 3 with a second equivalent circuit 8 including a third 2-qubit gate 8a that performs a gate operation of phase rotation of a second rotation angle to generate third circuits 5a, 5b,. The information processor 10 makes the quantum computer 1 execute the second quantum circuits 4a, 4b,. and the third quantum circuits 5a, 5b,., and outputs the average of the executed results as the executed result of the first quantum circuit 3.SELECTED DRAWING: Figure 1

A quantum processing unit comprising : rows comprising first qubits and second qubits, the first qubits and the second qubits being arranged alternatingly within each row, the first qubits and the second qubits forming columns, respectively; a first source configured to drive the first qubits with a first Rabi frequency; a second source configured to drive the second qubits with a second Rabi frequency, wherein two adjacent qubits within each row are subject to a first two-qubit interaction; one in every two columns of first qubits comprises a first special qubit provided between two adjacent second qubits, the first special qubit being such that it is driven with at least twice the first Rabi frequency by the first source, and the first special qubit being subject to a second two-qubit interaction with respect to each of the two adjacent second qubits, and one in every two columns of second qubits contains one second qubit, named second special qubit, such that it is driven with at least twice the second Rabi frequency by the second source.

The present invention discloses a quantum circuit, method, device, equipment, and medium for analyzing the magnetism of materials. The quantum circuit includes: n quantum bits arranged in ascending order from low to high, where n is the total number of lattice points in the lattice structure of the target material; the lattice structure is set as the spin structure of the target material, and each lattice point in the lattice structure is set as each spin of the target material; each quantum bit encodes the spin at each lattice point in the lattice structure; the first operation column includes n H gates, which act on the n quantum bits respectively; the circuit module includes multiple second operation columns and third operation columns that can be repeatedly operated. Each second operation column includes m R ZZ gates; the positions of the two-qubit for each R ZZ gate are determined according to the two nearest lattice points in the lattice structure; each third operation column includes n R X gates, which act on the n quantum bits respectively; the circuit module is located between the first operation column and the output end, and each R ZZ gate and R X gate carries a training parameter.

A circuit for reading out the state of a qubit 100 having singlet and triplet spin states comprising: a double quantum dot 101 forming a qubit 100 comprising first and second quantum dots 105, 106. The circuit comprises a cascade quantum dot 102 capacitively coupled to the second quantum dot 106; a charge reservoir 103 tunnel coupled to the cascade quantum dot 102; and readout circuitry 104 coupled to the reservoir 103. When a charge carrier tunnels between the first and second quantum dots 105, 106, a charge carrier tunnels between the cascade quantum dot 102 and the charge reservoir 103. A frequency source connected to a gate electrode or the charge reservoir 103 is configured to apply an alternating potential 111 at a first frequency, h, thereby to cause cyclic tunnelling of a charge carrier only when the qubit is in the singlet state which can be detected by the resonator circuit 104.

Embodiments of the present application provide a double quantum dot model simulation method and device, electronic equipment and storage medium. The scheme is as follows: a double quantum dot model is constructed as a to-be-simulated model; a Hamiltonian including a first energy is generated according to a performance parameter of the to-be-simulated model, wherein the first energy is a tunneling energy between electrons in the to-be-simulated model due to the spin-orbit coupling effect when the left and right quantum dots have opposite spins; based on the Hamiltonian, a target tunneling coefficient between source-drain electrodes and the left and right quantum dots in the to-be-simulated model is calculated; a target function relationship indicating a current in the to-be-simulated model is determined according to the target tunneling coefficient and a preset master equation, and the preset master equation is used to describe the dynamic change of the electron or hole distribution corresponding to the tunneling process in the to-be-simulated model; and the to-be-simulated model is simulated for drain current according to the target function relationship. Through the technical scheme provided by the embodiments of the present application, the drain current simulation of the double quantum dot model can be realized.

Methods, systems and apparatus for benchmarking quantum computing hardware. In one aspect, a method includes defining an initial circuit configured to operate on an array of qubits, wherein the initial circuit comprises multiple instances of the two-qubit gate, wherein each instance of the two-qubit gate performs a same operation on a respective pair of neighboring qubits in the array; partitioning the initial circuit into multiple layers, wherein instances of the two-qubit gate in a respective layer can be implemented in parallel; for each of the multiple layers: constructing benchmarking circuits for the layer, wherein each benchmarking circuit for the layer comprises one or more cycles of quantum gates, each cycle comprising: the layer of instances of the two-qubit gate, and a plurality of single qubit gates; implementing the constructed benchmarking circuits to obtain experimental benchmarking data; and adjusting control parameters of the control model using the experimental benchmarking data.

Aspects of the present disclosure relate to systems and methods in quantum information processing (QIP). The method includes determining a temporal profile of a trapping potential of an ion trap configured to trap a first trapped ion and a second trapped ion of an array of trapped ions for QIP and obtaining at least one characteristic of a first optical beam that is applied to the first trapped ion. The method includes synchronizing the at least one characteristic of the first optical beam and the temporal profile of the trapping potential and simultaneously applying the first optical beam to the first trapped ion based on the at least one characteristic and the trapping potential having the temporal profile to the ion trap. Optical beams including the first optical beam are applied to the first trapped ion and the second trapped ion.

The present disclosure provides a mounting method in which is used a linear optical circuit for quantum measurement that is a so-called pairwise fusion gate (PFG) having a function for stochastically projecting two inputted qudits onto the quantum entangled state of a two-qubit subspace. Specifically, provided is a pairwise fusion gate characterized by comprising a linear optical element and a photon detector, the pairwise fusion gate furthermore being characterized in that: the linear optical element and the photon detector are configured so that an input which has two d-dimensional qudits defined using d-rail coding (where d is an integer equal to or greater than 3), and in which there is no quantum entanglement between the two qudits, is stochastically projected onto a quantum entanglement state in a two-qubit subspace; and measurement results from the photon detector are used in determining the specific two-qubit subspace in which the projection onto the quantum entanglement state has been made.

Aspects of the present disclosure relate generally to systems and methods for use in the implementation and / or operation of quantum information processing (QIP) systems, and more particularly, to a fast single-mode spectroscopy technique that may be used in trapped-ion QIP systems. A method is described that includes performing a first measurement scan (full scan) across all motional modes of an ion chain in a trap followed by a second measurement scan on a single motional mode of the motional modes (single-mode scan). The second measurement scan determines a frequency shift associated with the single motional mode, which is applied to adjust the frequencies of all the motional modes. An implementation of two-qubit gates for quantum computations is based on the adjusted frequencies. A quantum computer or QIP system is also described that is configured to implement and perform the method described above.

The present disclosure relates to a method and apparatus for generating a quantum state preparation circuit, a quantum chip, an electronic device, a storage medium, and a computer program product. The method includes: determining a target qubit set with a binary tree restriction and applying a single qubit flip gate to a first target sub-node qubit; applying a two-qubit phase offset gate between sub-node qubits; applying a two-qubit SWAP gate between the first target sub-node qubit and a second target sub-node qubit; taking the sub-node qubits as the root node qubit and iteratively performing until the sub-node qubits are leaf node qubits; and applying the two-qubit phase offset gate with a path restriction between leaf node qubits and applying a single qubit phase offset gate to the leaf node qubits to obtain a quantum state preparation circuit.

The invention discloses a method for improving the electrical transport characteristic of etched graphene quantum dots and a device structure, and belongs to the technical field of low-temperature transport testing. The method comprises the following steps: manufacturing an etched graphene quantum dot device; carrying out preliminary electric transportation characterization by cooling; through several times of circular processing of sample electrode grounding protection-heating to more than 200K or room temperature-re-cooling-electrical transport characterization, the electrical transport property of the device is improved, and subsequent quantum dot fine charge stability diagram observation and control can be carried out. According to the optimization method, the coulomb blocking interval of the graphene quantum dots is successfully and gradually adjusted to the zero point from hundred volts through multiple times of temperature rising and falling thermal cycle treatment, grid voltage is conveniently applied, the double-quantum-dot charge stability diagram is obviously optimized and improved, and the yield of etched graphene quantum dot devices is greatly improved. In addition, the optimization method is easy to operate, obvious in effect and suitable for popularization.

A method for qubit initialization, comprising the steps of: (i) setting a dual qubit state of a pair of spin qubits to an arbitrary state; (ii) verifying a qubit state associated with the pair of spin qubits for a corresponding target state; and (iii) in response to determining that the qubit state is not the target state at step (ii), repeating steps (i) to (ii) until the qubit state is determined to be the target state. Determining the qubit state as the target state includes performing one or more Follicle spin blocking (PSB) checks and at least one dual qubit state transition operation on the pair of spin qubits.

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.