1117 results about "Qubit" patented technology

The technology relates to enhancing performance of quantum sensor operation in a noisy environment. Quantum neural networks are used to pre- and post-process analog signals to which qubits of a quantum sensor are exposed. Intra-processing using additional quantum neural networks may also be employed. This approach filters out noise from both the input analog signal and the system itself to achieve a very high signal to noise ratio. This permits the system to detect induced dynamics associated during exposure of the qubits to the analog signals. This enables the quantum sensor to sense a change in a state of a system under test, which can be beneficial for areas such as imaging, magnetometry, sensing electric fields, optomechanical sensors, quantum radar and other areas where enhanced signal to noise ratios are desired.

The invention relates to the technical field of geological disaster monitoring, in particular to a geological disaster monitoring method and system based on a quantum coupling effect. The method comprises the following steps: acquiring geological environment parameters of a target monitoring area; laying a quantum sensor network; initializing a quantum bit; the tunneling effect of quantum bits is excited by using microwave signals; obtaining quantum state data by using a quantum measurement technology; analyzing a coupling relationship among the geological environment parameters to realize geological disaster risk early warning; the causes and development tracks of geological disasters are traced, and monitoring and early warning strategies are optimized. Through a quantum sensor network and a multi-field coupling analysis model, ultrahigh-precision monitoring of stress, displacement, temperature and water level parameters is realized by using a quantum entanglement state, topology protection and time reversal technology, a disaster chain reaction path is revealed, cause and risk evolution are dynamically traced, the early warning reliability is remarkably improved, and the early warning effect is improved. And the monitoring mode is promoted to transition from passive response to active intervention.

In a general aspect, a quantum program can be automatically synthesized or compiled. In some implementations, a discretized state space is obtained. The discretized state space includes a plurality of states for one or more qubits of a quantum processor. A discrete action space is obtained. The discrete action space includes a plurality of unitary operations for the one or more qubits of the quantum processor. A policy that uses the discretized state space and the discrete action space to generate quantum programs for quantum state preparation is defined. A dynamic programming process is used to improve the policy. An initial state and a target state of the one or more qubits is identified. The policy is used to generate a quantum program to produce the target state from the initial state. The quantum program include a subset of the unitary operations in the discrete action space.

A multirail-encoded qubit can be implemented using a quantum system having a state space that includes a number M of distinct modes, where M is an integer greater than 2. The M modes are logically partitioned into two disjoint subsets (or “bands”), with each mode assigned to exactly one of the bands. The multirail encoding is defined such that a state in which any one of the modes in the first band is occupied and all modes in the second band are unoccupied maps to a logical 0 state of the qubit, and a state in which any one of the modes in the second band is occupied and all modes of the first band are unoccupied maps to a logical 1 state. Systems and methods for generating, measuring, and operating on multirail-encoded qubits are disclosed.

One or more systems, devices, methods of use and / or methods of fabrication provided herein relate to a device that can facilitate qubit measurement with isolation imposed between a quantum processor and a respective qubit measurement circuit and / or which respective qubit measurement circuit can have a small footprint, such as within a respective cryogenic chamber of a quantum system. According to one embodiment, a device comprises an isolator circuit having a bandpass filter configuration coupled between a pair of ports and the bandpass filter configuration comprising two or more poles. Two or more shunt resonators can be realized as the two or more poles, wherein the two or more shunt resonators can comprise DC SQUIDs and can be coupled together with one or more admittance inverters. A non-reciprocal signal transmission can be generated between the two ports by RF pumping the DC SQUIDs.

Method for operating a quantum computing element (1) with a network (2) of shuttling lanes (4) having multiple junctions (5) and multiple manipulation zones (7), wherein the method respectively comprises for a plurality of spin qubits (9):a) initializing the qubit (9),b) manipulating the qubit (9) in at least one of the manipulation zones (7),c) reading out the qubit (9),wherein at least one of the qubits (9) is shuttled along the network (2) of the shuttling lanes (4) between steps a) and c) so as to pass at least four different of the junctions (5).

An all-to-all coupled, high-fidelity, error-correctable quantum computer can scale to hundreds of qubits within a single cavity of moderate cooperativity with existing neutral atom technology. This quantum processor can enact teleported gates among any pair of qubits using a local Rydberg interaction between each qubit and a separate network of atoms that distribute entanglement via a cavity mode. Small atomic ensembles at network nodes allow for ultrafast, nondestructive readout with high fidelity by substantially shifting the resonance of even a poor-quality cavity. Fast readout enables near-deterministic entanglement distribution among network atoms despite cavity losses as well as syndrome measurements of qubit atoms for error correction.

A process is provided to generate a quantum circuit for preparing a target superposed state of a quantum bit register on a connectivity graph which comprises labeled edges and vertexes. The process comprises generating an initial layer of the quantum circuit which comprises a single-qubit gate to place the quantum bit register in an initial superposed state, and generating a sequence of layers following the initial layer, to generate the target superposed state. The sequence of layers comprises a plurality of layers of a same type of a controlled two-qubit gate which conditionally flips a state of a target quantum bit based on a state of a control quantum bit. A number of unique layers of the plurality of layers of the same type of a controlled two-qubit gate is no greater than a number of unique labels in a given set of labels for the connectivity graph.

A quantum logic circuit comprising: a plurality of quantum logic gates configured in a nested structure comprising layers; wherein each of the layers operates on a number of qubits to encode F features from at least one data point, wherein the number of qubits in a preceding layer is higher than the number of qubits in a subsequent layer, and wherein the F features are coherently aggregated in each subsequent layer without measurement thereby reducing the number of qubits required to encode the F features for processing.

The invention discloses a quantum bit mapping optimization method for hardware guidance and fidelity perception and a related device, and belongs to the field of quantum computing, and the method comprises the steps: defining each node in a hardware coupling graph of a target quantum processor as an initial community; evaluating all adjacent community pairs according to a reward function defined based on modularity and fidelity of candidate communities, selecting an optimal community pair for fusion, and taking the community with the largest current scale as an optimal candidate area; iteratively executing a community fusion step until a converged single community is obtained; and selecting an optimal candidate region with the physical quantum bit number greater than or equal to the logic quantum bit number of the quantum circuit to be mapped and the minimum scale, and outputting a mapping sub-graph. According to the method, through a recursive community fusion strategy, the operation range of the solver is restrained in a subspace with the scale greatly reduced and the quality better, the problem of combinatorial explosion caused by global search is fundamentally avoided, and the calculation overhead is greatly reduced.

A quantum computer verification apparatus includes: a division unit 1 that divides n qubits on which a quantum circuit U acts into m qubits and (n−m) qubits such that the number of CZ gates across the qubits becomes D=O(log n); a stabilizer operator calculation unit 2 that calculates a stabilizer operator {circumflex over ( )}sk for each k; an estimation unit 3 that randomly selects (i, j, i′, j′) T2 times for each k and calculates estimates of a real part of a value of the following expression to obtain T2 estimates;(-1)i·j+i′·j′⁢T⁢r[ρout[Qi,j†(∏i=1nZiki)⁢Qi′,j′]]an average calculation unit 4 that obtains an average of the T2 estimate for each k and sets the obtained average as an estimate of Tr[ρout{circumflex over ( )}sk] corresponding to each k, and a fidelity estimation value calculation unit 5 that obtains an average of estimates of Tr[ρout{circumflex over ( )}sk] corresponding to each k.

The invention relates to the technical field of quantum computing, and provides a linear complexity quantum state preparation method based on tensor decomposition and a quantum circuit construction system.The high-dimensional tensor is decomposed into a series of low-rank core tensors through continuous singular value decomposition, each core tensor in a core tensor sequence is expanded into a unitary matrix, and the unitary matrix is used as a quantum circuit; the unitary matrix sequence is mapped to quantum lines coupled using adjacent qubits, and the quantum lines are run to prepare a target quantum state. Based on this, the line generated by the method can approximately or accurately prepare a target quantum state only by coupling adjacent quantum bits, and is perfectly adaptive to quantum chips of linear or grid topologies such as superconducting and semiconductor quantum dots and the like.

A quantum computing system and methods for performing fusion based quantum computing on encoded qubits. A fusion controller sequentially performs a series of fusion measurements on respective photonic quantum modes of first and second encoded qubits to obtain a respective series of classical measurement results. For respective fusion measurements of the series of fusion measurements, a basis for performing the respective fusion measurement is selected based on classical measurement results of previous fusion measurements. An encoded fusion measurement result is determined based on the classical measurement results, and the encoded fusion measurement result is stored in a memory medium.

A method of performing a two-qubit gate operation includes computing, by a classical computer, a control pulse to be applied to a pair of trapped ions in a plurality of trapped ions in a quantum processor, each of the plurality of trapped ions having two frequency-separated states defining a qubit, wherein computing the control pulse comprises: computing a pulse function of the control pulse based on a phase-space closure condition and an auxiliary condition, and computing the pulse function of the control pulse further based on a gate angle condition, and applying, by a system controller, the control pulse, having the computed pulse function, to the pair of trapped ions.

A quantum computer system comprises first and second registers which are used to separate a quantum state into multiple subspaces of a 2n dimensional Hilbert space. A quantum state comprising 2n elements is defined on the first register, the first register comprising n qubits; a quantum state is defined on the second register, the second register comprising one or more qubits; and receiving a value k, where k is a binary integer such that 0 =< k =< n. The method further performing a bit-wise iteration process comprising: (i) performing a quantum entanglement between the registers to separate the quantum state on the first register into distinct subspaces of the Hilbert space which are indexed by the entangled values on the second register, and (ii) measuring an outcome on the second register to find a match with a portion of k, wherein said portion of k increases incrementally with the iteration process until the match is with all of k. The bit-wise iteration is used to separate the quantum state on the first register into subspaces of the Hilbert space, wherein elements of the subspaces have different Hamming weights, and one subspace contains only elements of Hamming weight k.

Quantum computers with a limited number of input qubits are used to perform machine learning processes having a far greater number of trainable features. A list of features of a field are divided into a plurality of feature groups. Each of the feature groups includes a respective group of some, but not all, of the features. A first machine learning process is performed to train a first instance of a quantum computer model, where the feature groups are used as inputs. Based on the first machine learning process being performed, a subset of the feature groups is selected for a second machine learning process. Thereafter, the second machine learning process is performed to train one or more second instances of the quantum computer model. The individual features of the selected subset of the feature groups are used as inputs for the second instances of the quantum computer model.

A quantum isolation zone (QIZ) controller executing on a quantum computing system, makes a determination to initiate, for a first QIZ of a plurality of different QIZs, a first local service instance of a global service instance that is executing on the quantum computing system, the first QIZ having a first set of qubits associated therewith. The first local service instance is caused to be initiated, and the QIZ controller modifies a local service data structure to indicate that the first local service instance is associated with the first QIZ.

An array of spin qubits relies on a gradient magnetic field to ensure that the qubits are separated in frequency in order to be individually addressable. Furthermore, a strong magnetic field gradient is required to electrically drive the EDSR of the qubits. Quantum dot devices and related methods and systems that integrate magnetic materials in the gates to provide a gradient magnetic field are disclosed. Magnetic materials in different gates may be of different heights to improve frequency separation of neighboring qubits. Unlike previous approaches to quantum dot formation and manipulation, various embodiments of the quantum dot devices disclosed herein may enable improved control over magnetic fields and their gradients to realize better frequency targeting of individual qubits, help minimize adverse effects of charge noise on qubit decoherence and provide good scalability in the number of quantum dots included in the device.

An information processing apparatus causes a quantum computer to perform a first gate operation in accordance with an ancilla state generation circuit representing a procedure of generating a code including a logical qubit representing an ancilla state and a gauge qubit representing a redundant degree of freedom other than the ancilla state. Next, the information processing apparatus causes the quantum computer to perform a second gate operation in accordance with an error detection circuit representing a procedure of detecting an error occurring in a plurality of physical qubits constituting the code generated by the first gate operation. Then, the information processing apparatus determines the presence or absence of the error on the basis of a measurement value obtained by the second gate operation, the measurement value indicating the state of the gauge qubit.

The invention discloses a quantum circuit conversion method and system, electronic equipment and a storage medium, and relates to the technical field of quantum circuit conversion, and the method comprises the steps: extracting a feature vector of a logic quantum circuit based on initial quantum bit mapping; the feature vector is input into a pre-trained decision tree, recommendation parameters of a line conversion algorithm are obtained, the decision tree is constructed by a training set, and the feature vector of each sample corresponds to the optimal parameter of the decision tree, namely the parameter with the minimum number of physical line gates; and configuring a line conversion algorithm by using recommended parameters, converting a logic line into a physical line, and ensuring that all two quantum bit gates meet quantum computer connected graph constraints and are equivalent in function. According to the method, adaptive parameter configuration can be achieved through the feature vectors and the decision tree, the line conversion quality is effectively improved, the number of physical line gates is remarkably reduced, and the quantum program execution efficiency is improved on the premise that function equivalence and connectivity are guaranteed.

Methods, systems, and apparatus for verified quantum phase estimation. In one aspect, a method includes repeatedly performing a experiment. Performing one repetition of the experiment includes: applying a second unitary to a system register of N qubits prepared in a target computational basis state; applying, conditioned on a state of a control qubit, a first unitary to the system register; applying an inverse of the second unitary to the system register and measuring each qubit to determine an output state of the system register; measuring the control qubit to obtain a corresponding measurement result m; and post-selecting on the target computational basis state by, in response to determining that the output state indicates that each qubit was in the target computational basis state prior to measurement, incrementing a first or second classical variable by (−1)m. Phases or expectation values of the first unitary are estimated based on the classical variables.

One example includes a resonator qubit system. The system includes a resonator qubit having a first resonant frequency and an ancilla resonator having a second resonant frequency that is detuned relative to the first resonant frequency. The system also includes a tunable coupler interconnecting the resonator qubit and the ancilla resonator. The system further includes a tuning element configured to provide a tuning signal to the tunable coupler to provide a phase rotation of a quantum state of the resonator qubit based on the first and second resonant frequencies.

Systems, methods, and computer-readable media of implementing a qubit gate for non-classical computing include implementing a qubit gate on a qubit of an array of qubits, wherein qubit states of said qubit are within a metastable manifold, wherein said qubit states are nuclear spin states, and wherein said qubit gate comprises a multi-photon transition through an intermediate metastable state.

The invention discloses a measurement and control system of a quantum computer, the quantum computer and a monitoring method. The system comprises a control signal generation unit, a control signal monitoring unit and a quantum analyzer, the control signal generation unit is used for generating a control signal for controlling quantum bits in a quantum processing unit of the quantum computer; the input end of the control signal monitoring unit is connected with the control signal generation unit, and the output end is connected with the quantum analyzer and the quantum processing unit. The control unit is used for coupling out a part of the control signal, demodulating the control signal, outputting the demodulated control signal to the quantum analyzer, and outputting the rest control signals to the quantum processing unit to control quantum bits; and the quantum analyzer is used for collecting and analyzing the demodulated signal output by the control signal monitoring unit. According to the invention, the real-time monitoring of the control signal can be realized, and in the monitoring process, the connection relationship of the measurement and control system of the quantum computer does not need to be additionally changed, so that the risk of misconnection possibly existing in the recovery circuit after inspection is also avoided.

Aspects of the disclosure include a technique for quantum lookup. Aspects include, in response to receiving an input, routing the input through first quantum routers to determine a first output. Aspects include routing the first output to at least one second quantum router, the at least one second quantum router feeding the first output to a gate tree, the gate tree generating a second output that is fed to qubits, the qubits performing operations generating readouts. Aspects include routing the readouts through third quantum routers, the third quantum routers arranged to output the readouts.

An electronic device includes a quantum processor including a plurality of qubits. The quantum processor runs a plurality of instances of a quantum program using a separate set of qubits from among the qubits for each instance of the quantum program. The quantum processor then sets quantum states for ancilla qubits from among the qubits based on quantum states of respective groups of associated qubits from the separate sets of qubits. The quantum processor next provides an output of the instances of the quantum program based on the quantum states of the ancilla qubits.

Systems and methods may include a quantum computer to train an AI model. A qubit computer-readable medium may store instructions that are run on the quantum computer to perform the method herein. The method may include the quantum computer: receiving data; agglomerating the data as a dataset; and storing the dataset as a set of qubits in superposition states. The method may include the quantum computer: initiating training of an AI algorithm to create the AI model; transition the set of qubits from the superposition states into a dataset in a binary state; protecting the dataset in the binary state with a cryptographic key; and providing the dataset to a GPU to run the GPU using the dataset to train the AI algorithm to create the AI model. The quantum computer may create the AI model at a higher rate than a digital computer creates the AI model.

A method, system, and computer program product for contextually calibrating quantum hardware. One or more contextual calibrations are selected or identified to minimize a contextual cost function of a quantum circuit. Examples of such contextual calibrations include, but are not limited to, tuning the amplitude, tuning the frequency duration, tuning the envelopes, recalibrating the error correction for specific qubits, recalibrating the measurement discriminator (identifies the specific quantum state), etc. The quantum hardware used to perform an execution of the quantum circuit may then be calibrated using the selected or identified contextual calibration(s). By minimizing the contextual cost function, such as via specific calibrations (e.g., tuning frequency duration, tuning amplitude), the performance of a general quantum device for a particular quantum circuit can be improved. For example, such contextual calibrations, such as at runtime, reduce the quantum device noise under different operating conditions thereby improving device performance.

A quantum processor is discussed. the quantum processor having a flux compensation circuit communicatively coupled to a first qubit. The flux compensation circuit includes a quantum flux parametron (QFP) flux pump circuit with a first QFP in communication with the first qubit and a storage circuit with a second Josephson junction and a storage loop coupled in series with the QFP flux pump circuit. The communication between the QFP flux pump circuit and the storage loop is mediated by the second Josephson junction. A first control line is in communication with the first Josephson junction and a second control line is in communication with the second Josephson junction. In use. flux stored in the storage loop back acts on the first qubit.

A computer-implemented method for determining a control sequence for performing a sequence of steps acting on qubits on a plurality of qubits on a quantum device, the method comprising obtaining a plurality of qubit entities, decomposing at least one qubit entity, combining at least two qubit entities, and compressing at least one determined combination of at least two qubit entities.