56 results about "Quantum measurement" patented technology

The invention relates to the technical field of quantum measurement, and discloses a high-speed arbitrary adjustable unbiased generalized measurement device for light quantum polarization bits, and the device comprises a high-speed adjustable z-axis rotation device; a high-speed adjustable y-axis rotating device; a measurement intensity high-speed adjusting device; a sigma z basis vector projection measurement device; a unit measuring device; and an electronics post-processing module. According to the invention, sigma z base vector projection measurement is constructed through an optical fiber polarization beam splitter (FPBS), unit measurement is constructed through an optical fiber beam splitter (FBS), and sigma z base vector unbiased generalized measurement with high-speed adjustable measurement intensity is realized in combination with a measurement intensity high-speed adjusting device and an electronics post-processing module. And the rotation of the measurement basis vector on the Bloch ball is realized through the high-speed adjustable z-axis rotating device and the high-speed adjustable y-axis rotating device, so that the high-speed arbitrary adjustable unbiased generalized measurement is realized.

The invention relates to the technical field of quantum measurement, in particular to a device for improving atom coherent population trapping efficiency and an implementation method. Screening candidate frequency points; judging a temporary frequency point; extracting concerned frequency points; correcting a target frequency point; c field and power adjustment; and applying a radio frequency field and performing frequency locking output. According to the invention, the radio frequency sweep frequency operation is carried out at the preset C field current value and the preset radio frequency power in the high-altitude field area, and the real-time collection and analysis of the transmitted light intensity, the internal temperature of the cavity and the external air pressure are combined, so that the target frequency point is screened from the original to-be-determined frequency points in a multi-level and multi-angle manner; and the C-field current and the radio frequency power are dynamically adjusted, so that high-precision locking of the radio frequency output frequency is further realized, the imprisoning efficiency of atom coherent population can be remarkably improved, the adaptive capacity and the compensation capacity of the system to external disturbance are enhanced, and the system has relatively high environmental robustness and frequency stability.

The invention provides a compensation method for asymmetric errors of a double-path weak measurement system and the double-path weak measurement system, which can be applied to the technical field of quantum measurement. The compensation method comprises the following steps: under the condition that wide-spectrum light passes through a double-path weak measurement system and the size of a signal which is weakly coupled with a weak coupling module is within a preset range, applying a square wave signal with a preset amplitude to a push-pull phase modulator, and performing binary detection by using an acquisition module to obtain four first detection signals; under the condition that the preset amplitude is not 0, determining a first error introduced by asymmetric loss of the double-path weak measurement system according to the corresponding four first detection signals; according to the four first detection signals corresponding to the square wave signal with the preset amplitude of 0 and the first error, determining a second error introduced by filter asymmetry of the double-path weak measurement system; according to the first error and the second error, asymmetric error compensation is carried out on the response formula, and it is ensured that the double-path weak measurement system has high sensitivity and stability.

The invention relates to the field of quantum measurement, and provides a CPT magnetometer magnetic measurement signal-to-noise ratio improving method and device based on a differential EIT-EIA signal. The CPT magnetometer solves the problem that a traditional CPT magnetometer is low in magnetic measurement signal-to-noise ratio due to the influence of environment temperature noise, laser stability and atomic gas chamber buffer gas. According to the main scheme, the CPT magnetometer comprises a laser generation module, a reference correction module, a differential detection module, a non-magnetic heating module and a signal processing module. The laser generation module generates reference / measurement double beams through the laser and the polarization regulation and control assembly; the reference correction module performs polarization conversion and optical path regulation and control on the reference light; the differential detection module divides the measurement light into two paths by adopting polarization beam splitting, the first path is subjected to polarization state conversion through an interference light path after frequency modulation, the second path is converted into circularly polarized light after optical fiber transmission, the two paths of light are coupled and then enter an atomic gas chamber for interaction, and differential detection is realized through a polarization beam splitting detector; and the non-magnetic heating module accurately controls the temperature of the air chamber by using a non-contact photo-thermal conversion technology.

Embodiments of the present invention relate to a system and method for monitoring optical communication channel during data transmission using a quantum measurement. Embodiments in accordance with the present invention is capable of estimating channel loss and added phase noise based on the quantum properties of faint light. All measurements utilizing system and method in accordance with embodiments of the present invention are local to the receiver, and additional information (or physical states) exchange between transmitter and receiver is not required.

The invention discloses a measurement and calibration system and method for a quantum current sensor, and belongs to the technical field of quantum measurement, and the system comprises a standard calibration system which comprises a DC / AC standard current source, a standard current sensor and a quantum current sensor; the microwave system is used for applying a microwave signal with a set frequency to the quantum current sensor so as to excite or regulate and control a quantum state energy level structure in the quantum current sensor; the optical system is used for exciting a quantum state in the quantum current sensor and acquiring a related optical response signal; and the signal processing system is used for respectively acquiring output signals of the standard current sensor and the quantum current sensor, analyzing and processing the output signals and generating calibration data for performing error compensation or performance correction on the quantum current sensor. According to the invention, real-time calibration of the quantum current sensor in a range of 10 [mu] A to 70 kA can be realized, and the linearity, sensitivity and temperature stability of the quantum current sensor are effectively improved.

This application relates to the field of quantum nondestructive testing technology, and discloses a quantum detection device and a xenon atom-based eddy current detection method. The quantum detection device includes an interconnected eddy current probe and a quantum measurement device. The quantum measurement device includes a xenon atom gas chamber for measuring the magnetic field strength of a target eddy current magnetic field. It acquires the target eddy current magnetic field of the target object, measures the magnetic field strength of the target eddy current magnetic field, and obtains the magnetic field strength distribution along the surface of the target object. Based on the magnetic field strength distribution, it detects thickness changes in the target object to obtain the weak point detection result. Its beneficial effect is that by measuring the eddy current magnetic field generated by the target object through a xenon atom gas chamber, it effectively utilizes the characteristics of xenon atoms—long coherence time and extremely low resonance frequency—thereby maintaining high sensitivity to capture weak magnetic fields at extremely low frequencies and obtaining a detection penetration depth far exceeding that of traditional sensors, achieving high-precision nondestructive testing of minute thickness differences inside the target object.

The invention provides a quantum state protocol construction system, and relates to the technical field of quantum communication, an Alice end modulates an optical pulse into a quantum optical pulse bearing two mutually orthogonal polarization states, and the quantum optical pulse is sent to a Bob end through an optical fiber link; the Bob end receives the quantum light pulses sent by the Alice end, extracts one light pulse, disorganizes the time sequence of the other light pulses, and returns the light pulses to the Alice end through an optical fiber link; and the Alice end realizes measurement of quantum state information of the light pulse by detecting the returned light pulse, and determines the type of one light pulse extracted by the Bob end. Based on the setting of a quantum multi-party security computing protocol device in quantum communication, the use of immature quantum related equipment such as a quantum memory and a high-dimensional entanglement quantum measurement device at present is avoided, and the application range of the protocol is enlarged.

The invention discloses an NV color center excitation laser adjusting method, a medium, a control device and measurement equipment, and relates to the technical field of quantum measurement. The method is used for the NV color center excitation laser debugging system. The system comprises a laser used for emitting target laser, at least two adjusting lenses used for expanding the target laser, and a focusing lens used for focusing the expanded target laser to generate laser spots. The method comprises the following steps: adjusting an adjusting lens according to a laser spot, so that the laser spot is matched with a laser incident surface of a target diamond; the adjusting lens is adjusted according to the fluorescence brightness generated when the NV color center in the target diamond is excited by the laser spot, so that the area of the laser spot is reduced, the position of the laser spot on the laser incident plane is adjusted, and the fluorescence brightness meets the target excitation requirement. Therefore, the NV color center position can be quickly positioned, the concentration ratio of the laser is enhanced, the laser intensity and the effective utilization rate are improved, and the accuracy and the sensitivity of measuring equipment are improved.

The invention discloses an electric power forest fire early warning method and device based on a quantum measurement technology. The method comprises the steps that multiple pieces of sensing data of a target position in a power line are acquired through a quantum sensor, and the multiple pieces of sensing data comprise temperature data, gas concentration data and electric field intensity data; based on the multiple pieces of sensing data, determining a forest fire risk level of the target position, the forest fire risk level including a low risk, a medium risk, a high risk or an extremely high risk; and performing early warning operation on the target position based on the forest fire risk level. According to the invention, the technical problems of low monitoring precision, slow response, easy interference and unsafe data transmission in a traditional electric power forest fire early warning method are solved.

The invention relates to the technical field of quantum measurement, in particular to a sensing measurement system based on a diamond NV color center, which is characterized in that a laser generates continuous laser, the continuous laser is converted into a horizontal polarization pulse laser beam through a Green Taylor prism and an acousto-optic modulator, and the horizontal polarization pulse laser beam enters a spatial light modulator for modulation through a beam expanding lens and a collimating lens; the modulated horizontal polarization pulse laser beam enters a dichroscope through a spatial filter and a half-wave plate to be reflected into an objective lens and is coupled and transmitted into a polarization maintaining optical fiber, the electron spinning state of a diamond NV color center is controlled through a microwave electric wire, the coupled horizontal polarization pulse laser beam is transmitted into the diamond NV color center through the polarization maintaining optical fiber, and the diamond NV color center is formed. Fluorescent light generated by stimulated radiation is transmitted to the optical filter group from the dichroscope, and is collected to a light-sensitive surface of the avalanche photodiode through the focusing lens. The movable vector quantum probe is integrally formed, and the sensitivity and accuracy of sensing measurement are improved.

The utility model discloses a microwave quantum sensing probe based on three-photon excitation. The microwave quantum sensing probe comprises a large rectangular prism, an atomic gas chamber, a color separation prism, a small rectangular prism, a first port, a second port, a third port, a detection light input optical fiber collimator, a decoration light and coupling light optical fiber collimator and a detection light output optical fiber collimator. The device is simple and compact in structure, and can solve the problems that an optical system in a conventional microwave quantum measurement system is complex and huge and cannot carry out portable detection. In addition, the device can also be suitable for a Rydberg atom three-photon excitation mode, and can be combined with the Rydberg atom three-photon excitation mode to build a transportable microwave measurement system suitable for the three-photon excitation mode.

The invention discloses a mobile phone appearance full-inspection system and method based on visual twinning, and relates to the technical field of mobile phone appearance detection.The method comprises the steps that a bionic optical sensor array is deployed, and mobile phone appearance data are collected; feature parameters are extracted, the optical features are coded into DNA sequences, and abnormal sites of the DNA sequences are automatically marked at material junctions; constructing a mobile phone appearance exclusive color gamut model; detection parameters are dynamically adjusted in the color gamut model, and the capture sensitivity to tiny chromatic aberration is enhanced; comparing chromaticity relevance of a standard prototype and a to-be-tested machine through quantum measurement, and automatically marking a problem area; and in combination with a mutation site in the DNA sequence, associating to a specific production process link through a pre-constructed causal association model. According to the invention, a four-dimensional color gamut model containing space, wavelength, time and observation angle is constructed, accurate detection of a gradient area is realized, and non-classical chromatic aberration correlation which cannot be captured by a traditional method is identified.

To improve performance for suppressing a quantum error.SOLUTION: A control device comprises: a quantum state calculation part for calculating a plurality of quantum states including a quantum state which has been influenced by a quantum error being a suppression object; a quantum measurement control part for measuring a matrix indicating Hamiltonian on a partial space which is defined by a positive semidefinite operator related to the plurality of quantum states, and an overlap matrix of the partial space with the positive semidefinite operator set as an identity operator, or brought into the quantum state influenced by the quantum error; an error suppression calculation part for calculating the peculiar energy of the Hamiltonian which is suppressed in the quantum error as a peculiar value of a generalized peculiar equation indicating the Hamiltonian; and a quantum error suppression part for calculating an expectation value of a physical amount from an objective physical amount of a quantum measurement on the basis of the calculated peculiar energy of the Hamiltonian.SELECTED DRAWING: Figure 5

The invention discloses a confocal light path system based on a diamond NV color center and a current detection method, and belongs to the technical field of quantum measurement, the confocal light path system comprises a main control module, an excitation light path module, a microwave driving module, a fluorescence collection module, a fluorescence processing module, an environment adaptive control module, an active feedback regulation and control module and a signal processing module, wherein the main control module is used for generating a synchronous time sequence control signal; the excitation light path module is used for generating, regulating and controlling excitation laser and guiding the excitation laser to the diamond NV color center sample; the microwave driving module is used for generating and applying a microwave field and a magnetic field to the diamond NV color center sample; and the active feedback regulation and control module is used for dynamically generating an optimization parameter instruction according to the preprocessed electric signal and the magnetic field information, and dynamically adjusting the working parameters of the excitation light path module and the microwave driving module. Through full-link modular integration and cooperative intelligent regulation and control, the NV color center current detection precision, stability and applicability are remarkably improved.

The present disclosure provides a mounting method in which is used a linear optical circuit for quantum measurement that is a so-called pairwise fusion gate (PFG) having a function for stochastically projecting two inputted qudits onto the quantum entangled state of a two-qubit subspace. Specifically, provided is a pairwise fusion gate characterized by comprising a linear optical element and a photon detector, the pairwise fusion gate furthermore being characterized in that: the linear optical element and the photon detector are configured so that an input which has two d-dimensional qudits defined using d-rail coding (where d is an integer equal to or greater than 3), and in which there is no quantum entanglement between the two qudits, is stochastically projected onto a quantum entanglement state in a two-qubit subspace; and measurement results from the photon detector are used in determining the specific two-qubit subspace in which the projection onto the quantum entanglement state has been made.

The invention discloses a long-wave time service signal receiving method based on a quantum antenna, and belongs to the technical field of quantum measurement. The core of the method is that Rydberg atoms are used as quantum antennas to receive signals; the method comprises the following steps: firstly, preparing cesium atoms into a highly excited state in a two-photon excitation mode of 852 nm and 509 nm laser; then, applying a direct-current electric field as a local oscillation field in the atomic gas chamber through an electrode plate; when a long-wave time service signal (such as a Roland-C signal) with the frequency of 100kHz arrives, superheterodyne frequency mixing is generated with a direct-current electric field in the atomic gas chamber based on an AC Stark effect, and a frequency mixing signal easy to detect is generated; and finally, the signal is detected through a photoelectric detector and an oscilloscope, and receiving of the time service signal is completed. The atomic system is used for replacing a traditional metal antenna, and the system has the remarkable advantages of high sensitivity, high anti-interference capability, small probe size, easiness in system integration and the like.

This invention discloses a laser excitation and adjustment system and method for NV center-excited lasers, relating to the field of quantum measurement technology. The system is used to transmit laser light to diamond containing NV centers and accurately irradiate them. It includes: a laser, a lens assembly, and a laser detection device; the laser emits the target laser light; the lens assembly is positioned in the optical path of the target laser and is used to expand and focus the target laser light to generate a laser spot; the laser detection device detects the laser spot and obtains the detection result, which is used to adjust the lens assembly to match the laser spot with the diamond laser incident surface; the laser and lens assembly are installed in the target system, and the laser spot irradiates and covers the laser incident surface; the laser power is adjusted so that the fluorescence brightness of the NV centers excited by the laser reaches the target requirement. Thus, a laser spot with a regular shape, high stability, and accurate irradiation of a cluster or a single NV center is obtained.

The present invention achieves quantum measurement with higher time resolution than in the past. This quantum measurement method measures a state change of an object (O) transported by a fluid, by using a plurality of quantum sensors (QSi) disposed along a flow path through which the fluid flows, and the method includes: an introduction step (S11) for introducing the object into the flow path; a measurement step (S12) for measuring the intensity of fluorescence emitted by each quantum sensor when illuminated with excitation light; and an estimation step (S13) for estimating the state of the object from the intensity of the fluorescence at times when a time (ti) required for the introduced object to be transported to each quantum sensor has elapsed.

The invention provides a medium-low vacuum pressure quantum measurement device based on dual-wavelength differential laser frequency stabilization, which comprises the following steps of: firstly, constructing the medium-low vacuum pressure quantum measurement device based on dual-wavelength differential laser frequency stabilization by applying a dual-wavelength differential theory, a dual-frequency laser collaborative frequency stabilization technology and the like, and stabilizing the resonant laser frequency to 10-15 orders of magnitude; the measurement precision of medium and low vacuum gas pressure is effectively improved, and the measurement lower limit is expanded to 10 <-2 > Pa magnitude, that is, the frequency stabilization effect based on an optical ultra-stable cavity and a PDH frequency stabilization technology can be effectively and greatly improved by the dual-frequency laser collaborative frequency stabilization system; secondly, an in-situ calibration laser frequency shift high-precision measurement system based on a rubidium atomic clock and an optical frequency comb is utilized to realize high-precision measurement and real-time calibration of the Hertz-magnitude resonant laser frequency shift; finally, interference of common-mode noise such as cavity length elastic deformation and temperature drift accompanied by dynamic pressure change is eliminated by using a gas refractive index measurement method based on a dual-wavelength difference theory, so that the middle-low vacuum gas pressure measurement precision based on an optical interference method is effectively improved, and the measurement lower limit is expanded.

The utility model discloses a measuring device for half-wave voltage of a phase modulator. The measuring device comprises a laser, a signal generator, an interferometer, photoelectric detection equipment and measuring equipment, one arm of the interferometer is provided with a phase modulator to be measured; the signal generator is a pulse signal generator. The utility model discloses a device for measuring the half-wave voltage of a phase modulator, which is characterized in that a pulse modulation electric signal is output by a pulse signal generator to drive a phase modulator to be measured, so that the adverse effect of interference optical signal phase drift on the half-wave voltage measurement can be effectively eliminated, and the accurate measurement of the half-wave voltage is realized. And the optical path is simple in structure and easy to construct, and is widely applied to a QKD system and a quantum measurement and metering system.

The invention discloses a diamond NV color center resonance frequency determination method and device, terminal equipment and a storage medium, and belongs to the field of quantum measurement. The method comprises the following steps: sweeping the frequency of a to-be-detected diamond by a first intensity microwave source, and determining a first formant target frequency according to a first magnetic resonance spectrogram; taking the lowest point frequency of the second magnetic resonance spectrogram as the first formant frequency after the second intensity microwave source sweep frequency; judging whether the decrease amplitude of the ODMR signal at a second formant target frequency obtained at the first formant frequency and the center frequency exceeds a preset threshold value or not, if not, performing frequency sweeping again by using the first intensity microwave source to obtain a third magnetic resonance spectrogram, performing frequency sweeping by using the second intensity microwave source to obtain a fourth magnetic resonance spectrogram, and determining the second formant frequency; if yes, determining a second formant frequency according to the fourth magnetic resonance spectrogram; and taking the first formant frequency and the second formant frequency as the NV color center resonance frequency of the to-be-measured diamond. By implementing the method, the problem of low accuracy of the resonance frequency in the prior art can be solved.

The invention discloses a quantum signal enhancement method, designs a related system, and discusses applications of the quantum signal enhancement method and the related system. According to the enhancement method, the quantum information processing capacity is integrated through auxiliary signals, joint operation and statistical analysis, and the system capacity exceeds the limitation of a single device through architecture design. An example system designed by the invention comprises: (1) a vacuum signal discrimination system which writes photon existence information into an auxiliary signal through combined operation and determines whether the signal is vacuum or not on the premise of not damaging an original signal; when the method is applied to quantum communication, the signal-to-noise ratio can be stabilized to be a constant value irrelevant to channel attenuation, so that any long-distance relay-free quantum communication is supported in principle; (2) a measurement enhancement system obtains a measurement copy by using combined operation compatible with a measurement operator, and the measurement precision is improved; (3) an iteration enhanced photon detection system starts from a single photon detector, and the detection capability is improved step by step through an iteration architecture; according to the scheme, the detection performance comparable to that of a superconducting single-photon detector is realized only based on a non-low-temperature element, the low-temperature environment requirement is avoided, and a large number of high-precision tasks are allowed to be implemented at a non-low temperature. The scheme has wide application prospects in the fields of light source preparation, empty signal detection, quantum measurement, quantum communication, quantum calculation and the like.

Methods and apparatus for measuring quantum systems involve: applying first optical pulses to the quantum system and monitoring for a first resulting photon after each first optical pulse; in response to detecting one or more first resulting photons, performing a π operation on the quantum system; and, after performing the π operation, applying second optical pulses to the quantum system and monitoring for a second resulting photon after each second optical pulse. The first and second optical pulses comprise a wavelength corresponding to a transition from a first basis state of the quantum system to an excited state. A measurement result is determined based on results of the monitoring.

The invention discloses a computing power migration method and device based on a quantum measurement technology. The method comprises the following steps: acquiring a real-time quantum signal of a power system; determining a plurality of target feature data based on the real-time quantum signal; the multiple pieces of target feature data are input into a preset migration decision model, a Pareto optimal solution set used for cross-system computing power migration is obtained, the migration decision model is constructed based on a quantum tunneling improved non-dominated sorting genetic algorithm, and the Pareto optimal solution set comprises multiple alternative migration schemes; determining a target migration scheme in the alternative migration schemes; and migrating the computing power resources of the first region to the second region based on the target migration scheme. The technical problems that in the prior art, cross-regional computing power migration cannot accurately match new energy output in real time, so that the new energy consumption rate is not increased enough, and computing power scheduling is mismatched with the new energy output are solved.

This invention discloses a method, medium, control device, and measuring equipment for adjusting NV center-excited lasers, relating to the field of quantum measurement technology. The method is used in an NV center-excited laser calibration system. The system includes a laser for emitting a target laser, at least two adjusting lenses for expanding the target laser beam, and a focusing lens for focusing the expanded target laser beam to generate a laser spot. The method includes: adjusting the adjusting lenses according to the laser spot to match the laser incident surface of the target diamond; and adjusting the adjusting lenses according to the fluorescence intensity generated by the laser spot excitation of the NV centers in the target diamond to reduce the laser spot area and adjust its position on the laser incident surface, ensuring the fluorescence intensity meets the target excitation requirements. This enables rapid positioning of the NV centers, enhances laser concentration, improves laser intensity and utilization efficiency, thereby improving the accuracy and sensitivity of the measuring equipment.

The present disclosure relates, inter alia, to a non-linear superconducting quantum circuit having a first mode and a second mode. The first mode and the second mode each have a corresponding resonant frequency. The circuit is configured such that the resonant frequency of the second mode is substantially 2N times the resonant frequency of the first mode when a predetermined current of constant intensity is applied to the circuit. The circuit inherently performs resonant 2N-to-1 photon switching between the first mode and the second mode, respectively, where N is a positive integer. This forms an improved non-linear superconducting quantum circuit. The circuit may stabilize the cat qubits when the circuit receives a predetermined current and the second mode is properly driven. In a symmetric version of the circuit, for quantum measurement, a magnetic flux line is developed to allow the radio frequency coupling to be coupled substantially only with the second mode and not with the first mode. This allows the stabilization function to be turned off and quantum measurements to be performed.

In order to solve the problem that the response speed and the dynamic range are difficult to consider when diamond is used for current quantum measurement at present, the invention provides a current measurement method based on microwave matching type phase-sensitive detection, quantum state information is rapidly extracted by selecting phase-sensitive detection frequency points in a jumping mode, the frequency band of formant offset after current change is calculated, and the response speed and the dynamic range are calculated. The number of microwave sweep frequency points is effectively reduced, and the phase-sensitive detection bandwidth is expanded, so that the response speed and the dynamic range of measurement are improved. The measuring system comprises a diamond sample, an optical integration system, an electrical integration system and an upper computer. In combination with the measurement method provided by the invention, the high sensitivity characteristic of diamond current measurement can be maintained, the measurement response speed and the dynamic range are remarkably improved, and the method has important application value for realizing large-range and high-real-time current measurement by a diamond NV color center quantum measurement system.

The invention provides a laser frequency hopping performance detection device, method and system and a cold atom interferometer, and belongs to the technical field of quantum measurement, the detection device comprises a reference laser, a high-speed photoelectric detector, a frequency discriminator, a reference frequency source, a PID controller, a voltage acquisition card and a microprocessor; the input end of the high-speed photoelectric detector is connected with the reference laser and the to-be-locked laser, and the to-be-locked laser outputs to-be-frequency-locked laser. The PID controller is connected with the to-be-locked laser, generates a voltage feedback signal and inputs the voltage feedback signal to a voltage control end of the to-be-locked laser; and the microprocessor is connected with the voltage acquisition card and the reference frequency source, and determines the frequency hopping speed of the laser to be locked according to the linear relationship between the frequency change of the laser to be locked and the voltage feedback signal. According to the detection device, in a field environment, the voltage feedback signal can be directly acquired through the voltage acquisition card to analyze the frequency hopping performance of the laser to be locked, the scheme is simple and easy to implement, and detection equipment such as a frequency counter does not need to be carried.