54 results about "Quantum logic" patented technology

In one embodiment, the disclosure relates to a method and apparatus for controlling the energy state of a qubit by bringing the qubit into and out of resonance by coupling the qubit to a flux quantum logic gate. The qubit can be in resonance with a pump signal, with another qubit or with some quantum logic gate. In another embodiment, the disclosure relates to a method for controlling a qubit with RSFQ logic or through the interface between RSFQ and the qubit.

The invention discloses a low-complexity quantum circuit simulation system, and belongs to the field of quantum computing. The low-complexity quantum circuit simulation system overcomes the technicalproblems in the prior art that the quantum circuit simulation storage space is too large and the calculation time is too long. The system comprises an input module, a storage module and an output module, the storage process of the storage module for data is as follows: (1) a mathematical model is established to represent the operation of a quantum state and quantum logic gate; (2) quantum bits aregrouped and the serial numbers of the quantum bits are rearranged; (3) degree reduction is conducted on a total operation matrix U0, and an output state is calculated. According to the system, a matrix element of a quantum state vector is directly operated by using an connotative inherent law of a quantum logic gate, at the same time, the method has expandability, in the future, a supercomputer can be used to simulate a quantum computer with more bits.

In a general aspect, randomized compiling techniques for quantum computing are described. In some aspects, an initial quantum-logic gate sequence is received. A modified quantum-logic gate sequence is generated by applying virtual random gates to the initial quantum-logic gate sequence, such that the initial quantum-logic gate sequence is logically equivalent to the modified quantum-logic gate sequence. The modified quantum-logic gate sequence can be provided to a quantum information processor for execution.

A quantum logic gate for qubits, suitable for receiving as inputs at least two polarization-encoded qubits, includes at least one partially polarizing beam splitter (PPBS), the beam splitter comprising a first waveguide and a second waveguide which are constructed in integrated optics, the first and second waveguides having a refractive index contrast of between 0.1% and 6% and a birefringence of between 10−6 and 6*10−5.

Techniques for high fidelity quantum teleportation include receiving an input photon representing a qubit. Ancilla photons are generated in a particular ancilla quantum state chosen to reduce a rate of error below a threshold error rate. The ancilla and the input photon are combined to populate output channels. A number of photons representing logical value 1 are measured in a subset of the output channels. A particular output channel is determined based on the measured number of photons. A teleported photon is obtained at the particular output channel with an error rate below the threshold error rate. These techniques allow the ancilla quantum state to be chosen to minimize the error despite the presence of losses and noise. Quantum logic operations are performed by teleporting two input qubits with the quantum state of the ancilla chosen to produce the desired logical result and reduce the error.

A method for quantum computing with a quantum system comprising a first energy level, a second energy level, and a third energy level. The first energy level and said second energy level are capable of being degenerate with respect to each other. In the method a signal is applied to the quantum system. The signal has an alternating amplitude at an associated frequency such that (i) the frequency of the signal correlates with an energy level separation between the first energy level and the third energy level or (ii) the frequency of the signal correlates with an energy level separation between the second energy level and the third energy level. The signal induces an oscillation in the state of the quantum system between the first energy level and the second energy level.

A superconducting logic cell includes at least one quantum phase-slip junction (QPSJ) for receiving at least one input and responsively providing at least one output, each QPSJ being configured such that when an input voltage of an input voltage pulse exceeds a critical value, a quantized charge of a Cooper electron pair tunnels across said QPSJ as an output, when the input voltage is less than the critical value, no quantized charge of the Cooper electron pair tunnels across said QPSJ as the output, where the presence and absence of the quantized charge in the form of a constant area current pulse in the output form two logic states, and the at least one QPSJ is biased with a bias voltage. The superconducting logic cell further includes at least one Josephson junction (JJ) coupled with the at least one QPSJ to perform one or more logic operations.

The invention belongs to the field of quantum computing, and particularly discloses a quantum circuit construction method and device. The method comprises the following steps: obtaining n quantum bitsand an N * N matrix; wherein n is a positive integer and N is equal to 2n; constructing a functional module for converting the quantum state | j) into a linear combination of the quantum state | k),the functional module implementing the conversion of the quantum state | j) into a matrix form of the functional module, the k representing a row of a matrix, the j representing a column of the matrix, the a and b representing a shift of the j and k; and constructing a quantum circuit corresponding to the functional module by utilizing a quantum logic gate. The invention provides a construction method of a quantum circuit, which is applied to quantum shift Fourier transform and is used for simulating quantum computation so as to fill up the blank of related technologies.

The invention discloses a calibration method belonging to the field of quantum computing, in particular to a single quantum logic gate operation. The calibration method comprises the following steps:determining that the modulation amplitude signal is a product of an adjustable proportion constant and a first digital signal; determining a plurality of pulse modulated signals having different modulated amplitude signals by changing the adjustable proportional constant; obtaining a distribution probability value corresponding one-to-one to each of the pulse modulated signals having different modulated amplitude signals; Taking the adjustable proportional constant as an independent variable and the distribution probability value as a dependent variable, performing wave oscillation exponentialattenuation fitting, and obtaining a wave oscillation period according to the fitting result, and recording the period as a standard period; the target quantum logic gate operation to be calibrated is determined, and the value of the adjustable proportion constant of the pulse modulation signal corresponding to the target quantum logic gate operation is determined according to the rotation angleand the standard period of the target quantum logic gate operation. The invention can realize the calibration of the operation of the single quantum logic gate.

The invention discloses a construction method of a quantum logic circuit for aiming at multiplication operation in an encryption technology field. The method comprises the following steps of constructing a base module, namely using a basic control Not gate and an exchange gate in the quantum logic circuit as a construction gate base of a basic circuit, and packaging the constructed basic circuit for forming a U device, thereby realizing add operation and multiplication operation; and constructing a high-grade circuit module. According to the construction method, a reversible logical design is utilized, and power consumption and behavior attribute of an electromagnetic field cannot be obtained through a traditional manner, thereby effectively preventing side channel attacks, and greatly reducing possibility of illegal crack. Better encryption effect of encryption technology is realized. Reversibility of the circuit can realize an encryption effect of 2n logic synthesis.

The invention discloses a quantum program processing method and device, a storage medium and an electronic device, and the method comprises the steps: combining quantum logic gates in a quantum program, and obtaining a combined quantum program; dividing execution time sequences of all quantum logic gates in the merged quantum program, wherein the at least two quantum logic gates are in the same execution time sequence. By utilizing the embodiment of the invention, the calculation efficiency of the quantum program can be improved.

The invention belongs to the technical field of quantum chip testing, and particularly discloses a method for generating quantum bit control signals. The method includes the steps that a first tag code and a first standard signal of each basic quantum logic gate in a corresponding reference quantum gate set sent by an upper computer are received; the first standard signals are stored, and first address codes for identifying the storage positions of the first standard signals are obtained; a target tag code and a target time code of each basic quantum logic gate in a corresponding target quantum program sent by the upper computer are received; first standard signals corresponding to the basic quantum logic gates in the target quantum program are obtained according to the target tag codes and the target time codes to serve as to-be-processed signals, the to-be-processed signals are processed, and the quantum bit control signals are obtained. The multi-bit quantum bit testing requirementscan be met, and the quantum bit control signal requirements needed by multi-bit quantum bit testing are provided.

The invention discloses a single-amplitude quantum computing simulation method. The method comprises the following steps of for each computing node of a distributed cluster, obtaining a target quantumprogram; constructing an undirected graph corresponding to the target quantum program; wherein the vertex of the undirected graph represents the quantum state of the operated quantum bit before or after the quantum logic gate is operated, and one edge of the undirected graph corresponds to one tensor; obtaining a quantum state corresponding to a to-be-measured target single amplitude, and calculating sub-amplitudes of the quantum state based on the quantum state and the undirected graph in cooperation with the GPU corresponding to the calculation node; wherein the sub-amplitudes are amplitudes corresponding to the undirected graph; and returning the sub-amplitudes to a main node of the distributed cluster so that the main node reduces each sub-amplitude to obtain the amplitude of the quantum state as a target single amplitude. The method is advantaged in that quantum computation simulation involving 50 or more quantum bits can be realized.

This invention concerns a method to switch on and off the exchange interaction J between electron spins bound to donor atoms. The electron spins have the role of ‘qubits’ to carry quantum information, and the exchange interaction J has the role of mediator for two-qubit quantum logic operations. The invention aims at exploiting the existence of a further magnetic interaction, the hyperfine interaction A, between each electron spin and the nuclear spin of the donor atom (301, 302) that binds the electron. The hyperfine interaction A, together with the ability to read out (504) and control the state of the nuclear spins, is used to suppress the effect of the exchange interaction J at all times, except while a quantum logic operation is being performed. In this way, the result of the quantum logic operation is not distorted after the operation has taken place. In a further aspect, the invention concerns an electronic device where the method can be practically implemented, and a large scale device made up of many of the devices.

A method for preparing a tunneling diode of quantum logic component includes applying gas phase epitaxial process to grow single crystal silicon (SCS) film and gas phase deposition process to grow silicon quantum dot film, using semiconductor quantum conveying means to simulate tunneling current character of tunneling diode component for making further regulation on folding character of tunneling current, growing p type of SCS film on heavy doped p type of single crystal silicon substrate first then growing n type of silicon quantum dot film on formed p type of film by gas phase epitaxial unit.

The invention belongs to the field of quantum computing, and particularly discloses an MPI multi-process-based single quantum logic gate implementation method, which comprises the following steps that: configuring N quantum bits, wherein the number of each quantum bit is bit n, the N is a positive integer, and the n is greater than or equal to 0 and less than or equal to N-1; determining quantum states and subscript values of the quantum states, the total number of the quantum states being 2N, and the subscript values being decimal values corresponding to the quantum states; initializing the quantum states; configuring 2M MPI communication-based processes, and sequentially and uniformly storing all the quantum states to the processes according to the subscript values, wherein M is an integer greater than or equal to 1, and N is greater than or equal to M + 1; and performing operation of the single quantum logic gate according to the bit of the quantum bit to be acted by the single quantum logic gate and the plurality of processes based on the MPI. According to the invention, the calculation capability and calculation efficiency of quantum calculation based on the single quantum logic gate can be improved.