41 results about "Quantum control" patented technology

A modular quantum computer architecture is developed with a hierarchy of interactions that can scale to very large numbers of qubits. Local entangling quantum gates between qubit memories within a single modular register are accomplished using natural interactions between the qubits, and entanglement between separate modular registers is completed via a probabilistic photonic interface between qubits in different registers, even over large distances. This architecture is suitable for the implementation of complex quantum circuits utilizing the flexible connectivity provided by a reconfigurable photonic interconnect network. The subject architecture is made fault-tolerant which is a prerequisite for scalability. An optimal quantum control of multimode couplings between qubits is accomplished via individual addressing the qubits with segmented optical pulses to suppress crosstalk in each register, thus enabling high-fidelity gates that can be scaled to larger qubit registers for quantum computation and simulation.

Systems and methods for obtaining information on a key in the BB84 (Bennett-Brassard 1984) protocol of quantum key distribution are provided. A representative system comprises a quantum cryptographic entangling probe, comprising a single-photon source configured to produce a probe photon, a polarization filter configured to determine an initial probe photon polarization state for a set error rate induced by the quantum cryptographic entangling probe, a quantum controlled-NOT (CNOT) gate configured to provide entanglement of a signal with the probe photon polarization state and produce a gated probe photon so as to obtain information on a key, a Wollaston prism configured to separate the gated probe photon with polarization correlated to a signal measured by a receiver, and two single-photon photodetectors configured to measure the polarization state of the gated probe photon.

All-optical quasi-phase matching (QPM) uses a train of counterpropagating pulses to enhance high-order harmonic generation (HHG) in a hollow waveguide. A pump pulse enters one end of the waveguide, and causes HHG in the waveguide. The counterpropagation pulses enter the other end of the waveguide and interact with the pump pulses to cause QPM within the waveguide, enhancing the HHG.

The invention relates to a precise control method of an atom spin SERF (Self-Exchange Relaxation-Free) state for stabilizing an atom spin device, which comprises the following steps that firstly, a precise equation is established for the atom spin SERF state, and a modulation method is adopted to measure the atom spin polarizability to establish a control target; then a control system model as precise as possible is established on the basis of an SERF model, and a parameter identification method is adopted to estimate unknown parameters of the model; and finally, according to the control target, a special structure design control law of the established model is fully used, i.e. the switching time, frequency, orientation and power of laser and the switching time of a modulation magnetic field are optimized, and the atom spin SERF state is precisely controlled in real time in accordance with a quantum control algorithm. By using the precise control method, the atom spin relaxation time is increased, and the problem of instability of scale factors of atom devices such as an atom spin gyroscope and an atom magnetometer based on the atom spin SERF effect is solved. The precise control method can be used for improving the long-time drift precision and the low-frequency sensitivity based on the SERF atom spin device.

The application discloses a quantum control micro-architecture, a quantum control processor and an instruction execution method, and relates to the field of quantum technology. The quantum control micro-architecture includes: a scheduler, an instruction memory, a plurality of processing units and corresponding private instruction buffers. The scheduler is used to determine the k sub-circuits executed in parallel in the quantum circuit, where k is an integer greater than 1, obtain the instructions corresponding to the k sub-circuits from the instruction memory, and store them in the private instruction buffers corresponding to the k processing units respectively. The target processing unit in the k processing units is used to obtain instructions corresponding to the target sub-circuits in the k sub-circuits from its corresponding private instruction buffer for execution; wherein, the k processing units execute their corresponding instructions in parallel. The present application adopts a sub-circuit level parallel solution, which has better scalability in the face of more complex quantum applications and increasing qubits.