50 results about "Quantum operation" patented technology

The invention discloses a quantum computing fluid dynamics simulation method based on a lattice Boltzmann method, and the method combines the parallelism of quantum computing with the advantages of the lattice Boltzmann method. An efficient fluid dynamics solving framework is constructed through a collision operator in a non-equilibrium correction term linearization lattice Boltzmann equation which is obtained by deducing through a Chapman-Enskog theory and a Maxwell equilibrium state function, wherein the non-equilibrium correction term linearization lattice Boltzmann equation contains an adjustable relaxation parameter. The quantum state in the Hilbert space can be converted through a quantum logic gate due to the characteristics of quantum calculation, so that the problem of complex calculation in fluid mechanics is efficiently solved. According to the method, the actual problem is coded into the quantum state vector of the quantum bit, the vector is directly changed through quantum operation to solve the problem, the quantum bit state does not need to be iterated one by one, for example, in the matrix and vector multiplication process, operation can be completed only by using a quantum logic gate to act on the input quantum state, and therefore the calculation efficiency is remarkably improved.

The invention relates to a method and system for quantum machine learning. In a described embodiment, a hybrid quantum classical computing method is implemented, the method comprising the steps of: receiving time-dependent input data of a dynamic system; transforming a first element of the input data using a plurality of transformation matrices to obtain a set of transformed data; and encoding the transformed data into a quantum circuit by performing a first set of quantum operations, the quantum circuit comprising a plurality of layers, the layers comprising a data encoding layer, a feedback layer, and a random transformation layer; encoding measurement feedback from a previous measurement vector into the quantum circuit is accomplished by performing a second set of quantum operations. The quantum circuit is to generate an updated measurement vector, and to generate a reservoir state based on the updated measurement vector, a previous reservoir state vector, and input data.

In a described embodiment, a hybrid quantum-classical computing method including receiving time dependent input data of a dynamical system, transforming a first element of the input data using a plurality of transformation matrices to obtain a set of transformed data, and encoding the transformed data into a quantum circuit by performing a first set of quantum operations is implemented. The quantum circuit includes a plurality of layers, wherein the layers include data encoding layers, feedback layers, and a random transformation layer is implemented. Encoding a measurement feedback from a previous measurement vector into the quantum circuit is implemented by performing a second set of quantum operations. The quantum circuit operates to generate an updated measurement vector and a reservoir state is generated based on the updated measurement vector, a previous reservoir state vector and the input data.

A quantum computational method is provided. The quantum computational method includes providing a physical quantum system (100) comprising constituents (50). The quantum computational method includes performing an encoded quantum computation on the physical quantum system. Performing the encoded quantum computation includes preparing at least a portion of the physical quantum system in an initial quantum state. Performing the encoded quantum computation includes evolving at least a portion of the physical quantum system to a final quantum state. Performing the encoded quantum computation includes measuring at least a portion of the physical quantum system to provide a read-out. During at least a portion of the encoded quantum computation, the quantum state of at least a portion of the quantum system is an encoded quantum state corresponding to a quantum error-correction code. The quantum error-correction code is a parity code that encodes logical qubits (10) into code qubits (20). The code qubits include parity qubits, wherein each parity qubit represents the parity of an associated subset of logical qubits. Each code qubit is physically implemented in a corresponding subsystem (50, 350) of the physical quantum system, wherein the subsystem comprises one or more constituents. During a first portion of the encoded quantum computation, the code qubits include a first code qubit duplication set (1350, 1450, 1550, 1651-1653, 1750) associated with a first logical qubit. The first code qubit duplication set includes at least three code qubits, wherein either (a) each code qubit in the first code qubit duplication set is a parity qubit representing the parity of a same first subset of logical qubits that includes the first logical qubit or (b) each code qubit in the first code qubit duplication set is a data qubit representing a quantum state of the first logical qubit. The quantum computational method further includes performing a first sequence of physical quantum operations on the physical quantum system during the first portion of the encoded quantum computation. The first sequence of physical quantum operations acts at least on the subsystems of the physical quantum system corresponding to the code qubits in the first code qubit duplication set. The first sequence of physical quantum operations is an encoded realization, via the parity code, of a first logical quantum operation (501-505, 1310, 1410, 1310, 1510, 1610, 1710, 1810) acting at least on the first logical qubit.

A method for performing a quantum computation, called the initial quantum computation, is disclosed, wherein the initial quantum computation is defined by at least a first set of one or more first-type quantum operations, wherein the first set of one or more first-type quantum operations each has one or more first rotation angles as parameters, and wherein each first-type quantum operation is a one-qubit rotation about a z-axis in a Bloch sphere by the respective first rotation angle.The procedure includes: representing the initial quantum computation by a function f that takes the first rotation angles as arguments; performing a Taylor expansion of the function f around zero, which leads to fundamental derivatives of the function f; for each specific derivative of at least one of the fundamental derivatives: using a parameter shift rule to express the specific derivative as a linear combination of a set of terms.

A quantum computational method is provided. The quantum computational method includes providing a physical quantum system (100) comprising constituents (50). The quantum computational method includes performing an encoded quantum computation on the physical quantum system. Performing the encoded quantum computation includes preparing at least a portion of the physical quantum system in an initial quantum state. Performing the encoded quantum computation includes evolving at least a portion of the physical quantum system to a final quantum state. Performing the encoded quantum computation includes measuring at least a portion of the physical quantum system to provide a read-out. During at least a portion of the encoded quantum computation, the quantum state of at least a portion of the quantum system is an encoded quantum state corresponding to a quantum error-correction code. The quantum error-correction code is a parity code that encodes logical qubits (10) into code qubits (20). The code qubits include parity qubits, wherein each parity qubit represents the parity of an associated subset of logical qubits. Each code qubit is physically implemented in a corresponding subsystem (50, 350) of the physical quantum system, wherein the subsystem comprises one or more constituents. During a first portion of the encoded quantum computation, the code qubits include a first code qubit duplication set (1350, 1450, 1550, 1651-1653, 1750) associated with a first logical qubit. The first code qubit duplication set includes at least three code qubits, wherein either (a) each code qubit in the first code qubit duplication set is a parity qubit representing the parity of a same first subset of logical qubits that includes the first logical qubit or (b) each code qubit in the first code qubit duplication set is a data qubit representing a quantum state of the first logical qubit. The quantum computational method further includes performing a first sequence of physical quantum operations on the physical quantum system during the first portion of the encoded quantum computation. The first sequence of physical quantum operations acts at least on the subsystems of the physical quantum system corresponding to the code qubits in the first code qubit duplication set. The first sequence of physical quantum operations is an encoded realization, via the parity code, of a first logical quantum operation (501-505, 1310, 1410, 1310, 1510, 1610, 1710, 1810) acting at least on the first logical qubit.

Quantum computing systems and methods for determining a state of a physical system are provided. In some examples, a method can include obtaining a defined function associated with the physical system, the defined function encoding an estimated value of at least one property to be simulated by a quantum computing system as a gradient of the defined function. The method can include implementing a quantum circuit on a plurality of qubits in a quantum computing system to perform a quantum operation (e.g., the Gilyén quantum gradient algorithm) on the plurality of qubits. The quantum operation is operable to determine the gradient of the defined function. The method can include determining the estimated value for the at least one property based at least on at least one of the plurality of qubits after implementation of the quantum operation.

A method for utilising a trapped ion for a quantum computing system, the trapped ion having an encoded quantum information unit configurable to be in any one of a plurality of quantum states, the method comprising: a quantum operation process that adjusts the quantum state of the quantum information unit, comprising the steps of: performing a check observation of the trapped ion; and raising an error flag in response to detecting the quantum information unit; and performing the corrective action in response to the error flag.

Systems and methods for performing fault-tolerant quantum operations for a four-legged cat code are provided. A quantum system includes an auxiliary qubit dispersively coupled to a first logical qubit, and the quantum system can be operated at least in part by generating and applying a first drive waveform to the auxiliary qubit, the first drive waveform including a first comb of pi 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 auxiliary qubit.

The invention discloses a fluid dynamics simulation method of a multi-physics field modular quantum circuit, which utilizes quantum bits as basic units of a system, converts an actual problem into a quantum state vector and directly solves the quantum state vector through quantum operation. Matrix and vector multiplication and other operations are carried out on the input quantum state through the quantum logic gate, and the calculation efficiency is greatly improved. According to the method, a local updating mechanism of a distribution function is adopted, so that the solution of a global equation is avoided; boundary processing is simple, convenient and flexible, better engineering application potential and physical consistency are achieved, and therefore an efficient, stable and expandable numerical calculation method is provided for the complex flow problem.

The invention relates to an apparatus 810 for generating a control signal for measuring a state of a quantum element of a quantum computer 830. A provision unit 811 provides a problem description. A transformation unit 812 transforms the problem description into a quantum mechanics representation. The transformation includes determining a unitary transformation that rotates an operator representing an observable value to be measured into a basis that produces a pure occupancy representation. A conversion unit 813 converts the quantum mechanical representation into a sequence of quantum operations including unitary transformation operations to be applied to quantum elements. The converting includes determining a unitary transform operation based on the determined unitary transform. A generation unit 814 generates signals for controlling the application of the determined sequence of quantum operations to the quantum computer, thereby preparing a quantum mechanical representation of the problem, and measuring an observable value indicative of a solution of the problem.

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.

Embodiments directed to designing corrective control signals are described. When implemented to drive a quantum operation, such corrective control signals can implement quantum gates that are insensitive to different noise types associated with the quantum operation. In one example, a method can include deriving noise cancellation conditions that are to be satisfied to define a corrective control signal that cancels different noise types associated with performing a quantum operation when the corrective control signal is used to drive the quantum operation. The method can further include constructing a space curve that satisfies the noise cancellation conditions in a multidimensional space. The space curve can be representative of the corrective control signal. The method can further include defining the corrective control signal based on the space curve.

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.

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 and techniques that facilitate phase factor determination in quantum signal processing are provided. Various embodiments described herein comprise a system, which can comprise: a memory that can store computer executable components; and a processor, operably coupled to the memory, that can execute at least one of the computer executable components that can receive a first target real-valued function and a second target real-valued function that represent a target transformation on a quantum state; determine a system of non-linear equations based on the first target real-valued function and the second target real-valued function, the system of non-linear equations comprising a number of phase factors that define parameters of quantum operations; determine the phase factors using a modified Newton method to iteratively solve the system of non-linear equations; and configure the quantum processor to apply the phase factors to a quantum circuit to implement the target transformation on the quantum state.

A method of determining a quantum operation being implemented by a linear-optical quantum device, the method comprising: repeatedly implementing the quantum operation on the linear-optical quantum device; and detecting at each photon detector of a number of photon detectors the presence or lack of presence of at least one photon to form detection data. The method further comprises determining, by a classical computer, a set of marginal probabilities using the detection data for each repetition of the quantum operation, forming, by the classical computer, a series of polynomial equations wherein the solutions to the series of polynomial equations are the set of marginal probabilities; and solving, by the classical computer, the series of polynomial equations to obtain an estimate of the quantum operation.

The present disclosure relates to a quantum computing method for performing quantum operations on a quantum system. The method comprises partitioning the quantum operations into multiple sets of quantum operations and assigning each set of quantum operations to a classical computer or a quantum computer. The method further comprises using each assigned classical computer to simulate the execution of the set of quantum operations. The method also comprises using each assigned quantum computer to execute the set of quantum operations. The execution of each set of quantum operations includes preparing a quantum state of the respective individual quantum system using the initial quantum state or an intermediate quantum state of the quantum system.The procedure involves combining the individual results to obtain a result of the initial quantum operations.

The invention provides a task abstraction and task management mechanism in a quantum operating system, which comprises the following steps: (1) quantum task abstraction: abstracting a quantum computing task into a quantum process and designing a quantum process control identifier to facilitate management and resource allocation of the quantum operating system; (2) quantum task management: performing management and resource allocation on the quantum process according to information in the quantum process identifier; and (3) designing a quantum process user interface, providing a Quantum library function and Qufork and Quexec system calling, and converting a quantum computing task required to be computed by a user into a quantum process for an operating system to manage. The mechanism provides a brand new normal form different from the existing quantum cloud service. By abstracting the quantum tasks into the quantum processes, an operating system can uniformly manage the quantum tasks, the fidelity of the quantum tasks is improved, and efficient concurrency is achieved. In addition, the mechanism can be deeply combined with quantum computing resource management, and development of a quantum operating system is promoted.

A method for optimizing a quantum operation to be applied on at least two quantum objects of a system of quantum objects, the method including the determination of an optimized pulse to be generated by at least one controlled laser for implementing the quantum operation on the at least two quantum objects while fulfilling a robustness criterion, the at least two quantum objects having a quantum state depending on the excitation level of the at least two quantum objects, the excitation level being chosen between 01, 10 and 11, 0 defining a de-excited state for a quantum object and 1 defining an excited state for a quantum object, the quantum state having a zero order term and a first order term.

This invention discloses a method, system, device, and storage medium for suppressing energy level leakage, relating to the field of quantum information processing. The method applies parametric modulation to qubits to establish and activate effective exchange coupling between qubits under dispersive coupling conditions, thereby performing a two-qubit entanglement gate operation. During the gate operation, a computational subspace control model and an energy level leakage model are constructed by performing representational and unitary transformations on the system's Hamiltonian. Based on these models, the entanglement gate control pulse is optimized. The energy level correction introduced by the parametric driving is dynamically compensated through modulation of the effective Rabi frequency of time-shaping and time-dependent detuning parameters, thus suppressing energy level leakage from the computational subspace to higher energy levels. Compared with existing technologies, this invention improves the controllability and fidelity of entanglement gate operations under complex energy level structures and is applicable to quantum operations in modular quantum systems.

A method, system and computer program product for computing noise channels for multi-qubit quantum operations. The learned Lindbladian describing the dynamics of a multi- qubit operation is received. The learned Lindbladian refers to a Lindbladian operator that has been derived or learned from data, such as low-weight observable measurements. The learned Lindbladian is then analyzed, such as using the ideal gate Hamiltonian (Hg) on n qubits, to identify the noise terms. A noise channel is then computed using a perturbative approach based on the identified noise terms. Examples of the perturbation approach include the Mangus expansion or the Dyson expansion. By using such a perturbative method to compute the noise channel, such a computation is performed in a controlled manner which exploits the locality of noise to reduce the complexity yet results in an accurate noise channel that correctly predicts how the physical noise acts on the qubits.

The embodiment of the invention discloses a performance analysis method for a quantum operation system and a related device, and relates to the technical field of quantum computer operation systems. Therefore, performance information used for indicating the processing performance of the quantum operating system can be generated according to the consumption information and the processing duration information of the quantum resources corresponding to each quantum computing task in the multiple quantum computing tasks. The performance information can indicate the quantum resource consumption condition and the processing duration condition when the quantum operation system processes each quantum calculation task in the multiple quantum calculation tasks, so that the performance information can specifically indicate the performance overhead and the processing efficiency when the quantum operation system processes the multiple quantum calculation tasks; therefore, the quantum operating system can be efficiently optimized by means of the performance information.

The present invention relates to a system and method for quantum processing framework development comprising an integrated quantum processing control device configured to interface with at least one quantum processing unit. The system includes a program interpretation processor for converting high-level quantum technique definitions into an abstract syntax representation, an intermediate representation processor for generating a hardware-independent graph data structure, a topology mapping processor for mapping logical qubits onto physical qubits based on connectivity and calibration data, and a scheduling processor for optimizing execution order in view of coherence and fidelity parameters. A pulse synthesis processor generates time-domain waveform instructions corresponding to mapped quantum gate operations, and a real-time control processor transmits synchronized control signals to digital-to-analog conversion circuitry while acquiring measurement data through analog-to-digital conversion circuitry. A hybrid synchronization processor coordinates classical post-processing and conditional quantum operations within deterministic latency constraints.

Disclosed is a method for performing a method for performing a quantum computation, referred to as initial quantum computation, the initial quantum computation being defined by at least a first set of one or more first type quantum operations, the first set of one or more first type quantum operations having as parameters one or more first rotation angles respectively, each first type quantum operation being a single-qubit rotation around a z- axis in a Bloch sphere by the respective first rotation angle. The method comprises: representing the initial quantum computation by a function f having as arguments the first rotation angles; performing a Taylor expansion of the function f around zero, resulting in foundational derivatives of the function f; for each specific derivative of at least one of the foundational derivatives: using a parameter shift rule for expressing the specific derivative as a linear combination of a set of terms.

A method of calibration of at least one parameter of an interaction sequence for performing a physical quantum operation defined on a single or multi-qubit system in a superconducting circuit based on cat qubits having a reduced bit-flip error rate as a noise-bias, the method comprising, for a qubit of the system affected by variations of the at least one parameter and with a list of at least one state of said qubit system, steps of, for a value of the at least one parameter and for each state of the list, preparing (S20) the state, applying (S30) the interaction sequence on the prepared state and with the parameter value, measuring (S40) bit-flipped and bit-unflipped populations of the affected qubit at an end of said applying, iterating (S50, S60, S10, S20) the said preparing, applying and measuring steps with varied values of the at least one parameter, sweeping a range of candidate values of the at least one parameter, and then identifying (S70), from populations measured during the iterating steps, an optimum of preservation of said noise-bias by the operation, and implementing (S80) as a calibrated value of the at least one parameter an inferred parameter value associated with the said identified optimum.

A quantum experiment execution system supporting parameter virtualization comprises a parameter path management unit used for establishing a mapping relation from a parameter path to a parameter value; the experiment description generation unit is configured according to static configuration and scanning requirements input by a user; the scanning point generator is used for analyzing the intermediate experiment description and creating a temporary parameter virtualization configuration environment in response to each compiling data point, and the environment integrates default parameter configuration values, the static configuration and specific numerical values of the compiling data points; the quantum operation flow generation unit is configured to obtain parameter values from the parameter virtualization configuration environment so as to generate a quantum operation flow used for being compiled into a hardware executable script; and the quantum compiling unit is used for compiling a configuration file to obtain from the parameter virtualization configuration environment and compiling the quantum operation process into a hardware orderable file.

Systems and techniques that facilitate phase factor determination in quantum signal processing are provided. Various embodiments described herein comprise a system, which can comprise: a memory that can store computer executable components; and a processor, operably coupled to the memory, that can execute at least one of the computer executable components that can receive a first target real-valued function and a second target real-valued function that represent a target transformation on a quantum state; determine a system of non-linear equations based on the first target real-valued function and the second target real-valued function, the system of non-linear equations comprising a number of phase factors that define parameters of quantum operations; determine the phase factors using a modified Newton method to iteratively solve the system of non-linear equations; and configure the quantum processor to apply the phase factors to a quantum circuit to implement the target transformation on the quantum state.

The invention refers to an apparatus 810 for generating control signals for measuring states of quantum elements of a quantum computer 830. A providing unit 811 provides a problem description. A transformation unit 812 transforms the problem description into a quantum mechanical representation The transformation comprises determining unitary transformations that rotate operators representing observables to be measured into bases that lead to a pure occupation number representation. A translation unit 813 translates the quantum mechanical representation into a sequence of quantum operations comprising unitary transformation operations to be applied to quantum elements. The translating comprises determining the unitary transformation operations based on the determined unitary transformations. A generation unit 814 generates signals for controlling the application of the determined sequence of quantum operations to the quantum computer such that the quantum mechanical representation of the problem is prepared and the observables indicative of the solution of the problem are measured.

Quantum private comparison (QPC) is a basic relational operation in quantum cryptography, and can compare whether two pieces of data are equal or not on the premise of not leaking specific numerical values of private data; an existing QPC protocol does not have the defects that the requirement for the quantum capacity of a user is high, that is, the steps are complex, the quantum bit efficiency is low, and the quantum bit efficiency is not higher than 100%; the technical difficulty and the cost are challenged; according to the invention, a QPC protocol is realized by using single photons with two degrees of freedom, and in the whole QPC process, only preparation and measurement of photons and quantum operations such as unitary operations on partial degrees of freedom of partial photons before measurement are involved; in this way, the implementation difficulty and cost of the protocol are greatly reduced, but the quantum bit efficiency of the protocol is extremely high and reaches up to 400%; according to the invention, the main defects of the existing QPC protocol are overcome; analysis shows that the method has the security and correctness of the QPC protocol.