121 results about "Quantum information processing" patented technology

Quantum information processing apparatus and methods are described. The apparatus comprises a device for defining a qubit and a reflectometry circuit for reading out a state of the qubit. The device comprises a semiconductor nanowire extending along a first direction having first and second obtuse or acute edges running along the first direction, gate dielectric overlying the first and second edges of the nanowire and a split gate running across a section of the nanowire in a second, transverse direction, the split gate comprising first and second gates overlying the first and second edges respectively. The reflectometry circuit comprises a resonator coupled to the first or second gate.

The invention provides a sequential control signal generation method of a cold ion quantum information processor. Radio frequency signal and digital signal parameters are set through a principal computer command on a principal computer; the principal computer command is converted into a machine command which is transmitted to a sequential control FPGA; the sequential control FPGA executes the machine command and digital signals and radio frequency signals are output through a conversion module and a radio frequency synthesis module. The invention also provides a sequential control signal generation device of a cold ion quantum information processor. The device comprises a principal computer, a sequential control module, a radio frequency synthesis module and a conversion module. According to the invention, sequential control signals for experiments are described intuitively; programmed principal computer commands can be used repeatedly, so that repeated work is prevented and improvement can be made according to experiment results conveniently; the parameters such as the frequency, the phase and the amplitude of radio frequency signals can be changed conveniently; multiple paths of control signals can be controlled accurately to work cooperatively; the extendibility is great.

Semiconductor micro- and nanotubes allow the incorporation of ordered structures such as quantum wells and quantum dots into them providing the potential for ultralow threshold micro- and nanoscale lasers for use in applications such as future ultrahigh-speed photonic systems as well as quantum information processing. According to the invention a means of manufacturing these with high reproducibility, low processing complexity, and at high densities is provided. Also provided is a means of releasing these micro- and nanotubes with low stress and a method of “pick-and-place” allowing micro- and nanotubes to be exploited in devices integrated on substrates that are either incompatible with the manufacturing technique or where the area of substrate required to manufacture them is detrimental to the cost or performance of the circuit.

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.

Techniques are provided that use the quantum Zeno effect to implement practical devices that use single photons as the qubits for quantum information processing. In the quantum Zeno effect, a randomly-occurring event is suppressed by frequent measurements to determine whether the event has occurred. The same results can be obtained by using atoms or molecules or ions to react to the occurrence of the event. Techniques include directing one or more input qubits onto a device and applying a quantum Zeno effect in the device. The quantum Zeno effect is applied by consuming one or more photons in the device under conditions in which photons, that would otherwise be output by the device, do not represent a result of a particular quantum information processing operation. Devices implemented using the quantum Zeno effect can operate with low error rates without the need for high efficiency detectors and large number of ancilla.

The invention provides a nano-diamond film with Si-V luminescence and a preparation method thereof. The nano-diamond film is prepared on a single crystal silicon substrate by use of a hot filament chemical vapor deposition method; heat preservation is performed on the film for 5-150 minutes in air at a temperature ranging from 500 to 700 DEG C, and then the nano-diamond film with Si-V luminescence is obtained. The nano-diamond film prepared has relatively high Si-V luminescence intensity which has very important scientific significance and engineering value for the application of the nano-diamond film in the fields such as single photon sources, quantum information processing, photoelectric devices, biomarkers, semiconductor devices and field emission displays.

Apparatus and methods for performing quantum computations are disclosed. Such quantum computational systems may include quantum computers, quantum cryptography systems, quantum information processing systems, quantum storage media, and special purpose quantum simulators.

A quantum information processing device including a semiconductor substrate. An optical resonator is coupled to the substrate. The optical resonator supports a first photonic mode with a first resonator frequency. The quantum information processing device includes a non-gaseous chalcogen donor atom disposed within the semiconductor substrate and optically coupled to the optical resonator. The donor atom has a transition frequency in resonance with the resonator frequency. Also disclosed herein are systems, devices, articles and methods with practical application in quantum information processing including or associated with one or more deep impurities in a silicon substrate optically coupled to an optical structure.

Techniques for performing quantum information processing using an asymmetric error channel are provided. According to some aspects, a quantum information processing includes a data qubit and an ancilla qubit, the ancilla qubit having an asymmetric error channel. The data qubit is coupled to the ancilla qubit. The ancilla qubit may be driven with a stabilizing microwave field to create the asymmetric error channel.

A method for preparing an entangled quantum state of an atomic ensemble is provided. The method includes loading each atom of the atomic ensemble into a respective optical trap; placing each atom of the atomic ensemble into a same first atomic quantum state by impingement of pump radiation; approaching the atoms of the atomic ensemble to within a dipole-dipole interaction length of each other; Rydberg-dressing the atomic ensemble; during the Rydberg-dressing operation, exciting the atomic ensemble with a Raman pulse tuned to stimulate a ground-state hyperfine transition from the first atomic quantum state to a second atomic quantum state; and separating the atoms of the atomic ensemble by more than a dipole-dipole interaction length.

The invention provides a single granule layer nanometer diamond film with strong Si-V luminescence, and a production method thereof. The method comprises the following steps: producing a single granule layer nanometer diamond film with the thickness of 500-700nm on a monocrystalline silicon substrate by adopting a hot filament chemical vapor deposition technology; and carrying out heat insulation on the film in 600DEG C air for 10-50min to produce the single granule layer nanometer diamond film with strong Si-V luminescence. The nanometer diamond film obtained in the invention has single granule layer characteristics and has a thickness of 500-700nm, the speak shape of the Si-V luminescence peak of the film is sharp, the Si-V luminescence intensity is greatly improved, and the preparation is of great scientific and engineering significance to realize application of the film in fields of single photon sources, quantum information processing, photoelectron devices, biological markers, semiconductor devices and field emission displays.

The invention discloses a simple and reliable method for preparing any Werner state, comprising a step of preparing an entanglement light source, in which photon pairs are entangled by using laser topump nonlinear crystals to generate a spontaneous parametric down conversion process, and a step of constructing a controllable depolarized channel, in which a completely mixed state is introduced byacting the controllable depolarized channel on one photon. Sandwich-shaped crystals are adopted for the nonlinear crystals and comprise two BBO crystals and a real zero-order half-wave plate disposedbetween the two BBO crystals. The controllable depolarized channel is composed of a Sagnac ring, a complete destructive phase channel and a state superposition portion, the Sagnac ring is of a rectangular structure, and a half-wave plate is disposed between two reflectors thereof; the complete destructive phase channel is composed of two destructive phase crystals and a half-wave plate therebetween; and the state superposition portion comprises a BS. The simple and reliable method is convenient to adjust and high in feasibility, and can be applied to the fields of quantum information processing and quantum communication.

The invention discloses a device and system for measuring the orbital angular momentum spectrum of a light beam. The device just needs to enable a to-be-measured light beam to be transmitted in an optical axis direction of a system, and obtains a far-field diffraction spot gray scale pattern at a receiving end. The orbital angular momentum spectrum of the incident light beam can be obtained through a calculation system provided by the invention. The device is very simple, and the optical path is easy to adjust. The device is higher in operability, and just needs to obtain the far-field diffraction spot gray scale pattern, wherein other operations are automatically completed by a host. Compared with the conventional technology of orbital angular momentum spectrum measurement, the device and system are improved greatly. The device and system can be used for the technology of light communication, the field of quantum information processing and the technology of optical tweezers.

The invention provides a method for realizing quantum circuit design through quantum Haar wavelet transformation, and belongs to the field of quantum information processing. According to the method, the existing quantum Fourier transform implementing technology is perfected and improved, and implementing circuits of two pieces of multi-layer quantum Haar wavelet transformation and two pieces of multi-layer quantum Haar wavelet inverse transformation are established separately by using extended tensor product and basic quantum bit gate (comprising quantum bit controlled door and single quantum bit gate). Based on analysis of the complex rates of the implementing circuits of the quantum Haar wavelet transformation and the quantum Haar wavelet inverse transformation, the complex rates of the implementing circuits of the two pieces of multi-layer quantum Haar wavelet transformation and the two pieces of multi-layer quantum Haar wavelet inverse transformation are Theta(n2) for one data set with 2n elements, and other typical and rapid Haar wavelet transformation cannot achieve the aim. The method is suitable for the fields of algorithms such as compression, denoising, encryption and decryption of images of actual information processing application, and has important significance in popularization of perfection and application of a quantum computing theory.

A quantum information processing system comprises a light source, a detector, at least one spatial light modulator and at least one optical lens. The light source is configured to provide a beam of entangled photons. The at least one optical lens is configured to project the resultant beam onto the spatial light modulator, either by direct imaging or by performing a full or partial optical Fourier transform. Said spatial light modulator includes a plurality of discrete pixels and is configured to select one or more of the plurality of discrete pixels to generate a resultant beam from said beam of entangled photons. The resultant beam from said spatial light modulator is projected onto the detector. For optical computation, such as search algorithms, the configuration and projections are repeated to find the optimal solution.

The invention in various embodiments is directed to quantum information processing elements and quantum information processing platforms employing such elements. In one aspect, the quantum information processing elements are formed with self-assembling protein molecules.