Isotropic laser cooling(ILC)is widely recognized for its distinct advantages and demonstrates significant potential in quantum precision measurements and quantum sensing technologies.The morphology and density distrib...Isotropic laser cooling(ILC)is widely recognized for its distinct advantages and demonstrates significant potential in quantum precision measurements and quantum sensing technologies.The morphology and density distribution of the cold atomic cloud generated by ILC are strongly influenced by the distribution of cooling light and the structural geometry of the cavity,making precise characterization and optimization of cold atom distribution essential for practical applications.In this paper,we present an innovative flat diffuse cavity design with the dimensions approximating a quasi-two-dimensional configuration,which generates a sheet-like isotropic laser field inside the cavity through diffuse reflections.We thoroughly characterized the system’s performance under different optical parameter settings.A two-dimensional(2D)movable detection system was employed to detect the quasi-two-dimensional distribution of cold atoms.These results demonstrate the ability of ILC to produce diverse morphological and density distributions of cold atoms,which we anticipate will be suitable for quantum sensing.展开更多
Single-electron spins in quantum dots are the leading platform for qubits,while magnons in solids are one of the emerging candidates for quantum technologies.How to manipulate a composite system composed of both syste...Single-electron spins in quantum dots are the leading platform for qubits,while magnons in solids are one of the emerging candidates for quantum technologies.How to manipulate a composite system composed of both systems is an outstanding challenge.Here,we use spin-charge hybridization to effectively couple the single-electron spin state in quantum dots to the cavity and further to the magnons.Through this coupling,quantum dots can entangle and detect magnon states.The detection efficiency can reach 0.94 in a realistic experimental situation.We also demonstrate the electrical tunability of the scheme for various parameters.These results pave a practical pathway for applications of composite systems based on quantum dots and magnons.展开更多
The accuracy of power system measurements directly affects the safe and stable operation of power grids. This study explores the application prospects of quantum sensing technology in power system measurements. The re...The accuracy of power system measurements directly affects the safe and stable operation of power grids. This study explores the application prospects of quantum sensing technology in power system measurements. The research first analyzes the limitations of traditional measurement techniques, such as electromagnetic interference sensitivity and measurement accuracy bottlenecks. It then introduces the basic principles of quantum sensing, including concepts like quantum entanglement and superposition states. Through theoretical analysis and numerical simulations, the study assesses the potential advantages of quantum sensors in current, voltage, and magnetic field measurements. Results show that quantum magnetometers offer significant improvements in accuracy and interference resistance for current measurements. The study also discusses the application of quantum optical technology in high-voltage measurements, demonstrating its unique advantages in improving measurement dynamic range. However, quantum sensing technology still faces challenges in practical applications, such as technological maturity and cost. To address these issues, the research proposes a phased implementation strategy and industry-academia collaboration model. Finally, the study envisions future directions combining quantum sensing with artificial intelligence. This research provides a theoretical foundation for innovative upgrades in power system measurement technology.展开更多
Error correction has long been suggested to extend the sensitivity of quantum sensors into the Heisenberg Limit. However, operations on logical qubits are only performed through universal gate sets consisting of finit...Error correction has long been suggested to extend the sensitivity of quantum sensors into the Heisenberg Limit. However, operations on logical qubits are only performed through universal gate sets consisting of finite-sized gates such as Clifford + T. Although these logical gate sets allow for universal quantum computation, the finite gate sizes present a problem for quantum sensing, since in sensing protocols, such as the Ramsey measurement protocol, the signal must act continuously. The difficulty in constructing a continuous logical op-erator comes from the Eastin-Knill theorem, which prevents a continuous sig-nal from being both fault-tolerant to local errors and transverse. Since error correction is needed to approach the Heisenberg Limit in a noisy environment, it is important to explore how to construct fault-tolerant continuous operators. In this paper, a protocol to design continuous logical z-rotations is proposed and applied to the Steane Code. The fault tolerance of the designed operator is investigated using the Knill-Laflamme conditions. The Knill-Laflamme condi-tions indicate that the diagonal unitary operator constructed cannot be fault tolerant solely due to the possibilities of X errors on the middle qubit. The ap-proach demonstrated throughout this paper may, however, find success in codes with more qubits such as the Shor code, distance 3 surface code, [15, 1, 3] code, or codes with a larger distance such as the [11, 1, 5] code.展开更多
This work theoretically studies the Bose–Hubbard(BH)model in a ring geometry in a rotating frame.We obtain an effective Hamiltonian by using unitary transformation,where the effect of the rotating reference frame is ...This work theoretically studies the Bose–Hubbard(BH)model in a ring geometry in a rotating frame.We obtain an effective Hamiltonian by using unitary transformation,where the effect of the rotating reference frame is introducing additional phases to the hopping constant.Within the mean-field theory,the phase transition edge depends not only on the particle number and ring radius,but also on rotation velocity.Therefore,we propose a sensing method of the rotation velocity using the phase transition edge of the Bose–Hubbard model.At the exact phase transition edge where this sensing method is most sensitive,the resolution depends on the rotation velocity,the particle number and the ring radius,while it is independent of the parameters in the Bose–Hubbard model such as the hopping constant and the on-site interaction.展开更多
A maximal photon number entangled state,namely NOON state,can be adopted for sensing with a quantum enhancedprecision.In this work,we designed silicon quantum photonic chips containing two types of Mach-Zehnder interf...A maximal photon number entangled state,namely NOON state,can be adopted for sensing with a quantum enhancedprecision.In this work,we designed silicon quantum photonic chips containing two types of Mach-Zehnder interferometerswherein the two-photon NOON state,sensing element for temperature or humidity,is generated.Compared with classicallight or single photon case,two-photon NOON state sensing shows a solid enhancement in the sensing resolution andprecision.As the first demonstration of on-chip quantum photonic sensing,it reveals the advantages of photonic chips forhigh integration density,small-size,stability for multiple-parameter sensing serviceability.A higher sensing precision isexpected to beat the standard quantum limit with a higher photon number NOON state.展开更多
Quantum systems that undergo quantum phase transitions exhibit divergent susceptibility and can be exploited as probes to estimate physical parameters.We generalize the dynamic framework for criticality-enhanced quant...Quantum systems that undergo quantum phase transitions exhibit divergent susceptibility and can be exploited as probes to estimate physical parameters.We generalize the dynamic framework for criticality-enhanced quantum sensing by the quantum Rabi model(QRM)to its anisotropic counterpart and derive the correspondingly analytical expressions for the quantum Fisher information(QFI).We find that the contributions of the rotating-wave and counterrotating-wave interaction terms are symmetric at the limit of the infinite ratio of qubit frequency to field frequency,with the QFI reaching a maximum for the isotropic QRM.At finite frequency scaling,we analytically derive the inverted variance of higher-order correction and find that it is more affected by the rotating-wave coupling than by the counterrotating-wave coupling.展开更多
Quantum sensing has been receiving researcher's attention these years due to its ultrahigh sensitivity and precision. However, the bandwidth of the sensors may be low, thus limiting the scope of their practical ap...Quantum sensing has been receiving researcher's attention these years due to its ultrahigh sensitivity and precision. However, the bandwidth of the sensors may be low, thus limiting the scope of their practical applications. The low-bandwidth problem is conquered by feedback control methods, which are widely utilized in classic control fields. Based on a quantum harmonic oscillator model operating near the resonant point, the bandwidth and sensitivity of the quantum sensor are analyzed. The results give two important conclusions: (a) the bandwidth and sensitivity are two incompatible performance parameters of the sensor, so there must be a trade-off between bandwidth and sensitivity in practical applications;(b) the quantum white noise affects the signal to be detected in a non-white form due to the feedback control.展开更多
Quantum technologies,mainly quantum computing and quantum sensing are emerging as new applications of quantum mechanics for practical use.Two notable advancements in quantum computing and quantum sensing respectively ...Quantum technologies,mainly quantum computing and quantum sensing are emerging as new applications of quantum mechanics for practical use.Two notable advancements in quantum computing and quantum sensing respectively are Shor’s algorithm and nitrogen vacancy centers in diamond lattices.Shor’s algorithm leverages certain properties of quantum computers to factor large numbers faster than any classical algorithm.Nitrogen vacancy centers leverage spin defects to sense even very small signatures of magnetic fields.This review article aims to provide a pedagogical introduction and overview of these emerging platforms for quantum technology.展开更多
Optically detected magnetic resonance(ODMR)has emerged as a powerful technique for quantum sensing,enabling high-sensitivity detection of physical quantities even at room temperature.Solid-state defects,such as nitrog...Optically detected magnetic resonance(ODMR)has emerged as a powerful technique for quantum sensing,enabling high-sensitivity detection of physical quantities even at room temperature.Solid-state defects,such as nitrogen-vacancy(NV)centers in diamond,have demonstrated remarkable capabilities in this domain[1–4].However,these systems are limited by their rigid lattice structures and lack tunability.展开更多
Negatively charged boron vacancy(V_(B)^(-))spin defects are stable in nanoscale hexagonal boron nitride(hBN)flakes,which can be easily integrated into two-dimensional materials and devices to serve as both sensors and...Negatively charged boron vacancy(V_(B)^(-))spin defects are stable in nanoscale hexagonal boron nitride(hBN)flakes,which can be easily integrated into two-dimensional materials and devices to serve as both sensors and protective materials.Ion irradiation is frequently employed to create V_(B)^(-)spin defects in hBN.However,the optimal ion irradiation parameters remain unclear,even though they play a crucial role in determining the depth and density of the defects,which in turn affect sensing sensitivity.In this work,we optimize the carbon ion irradiation parameters for creating V_(B)^(-)spin defects by varying the irradiation dose and the incident angle.For 30 keV carbon ion irradiation,the optimal irradiation dose to create a V_(B)^(-)ensemble is determined to be 4×10^(13)ions/cm^(2),and both continuous and pulsed optically detected magnetic resonance measurements are used to estimate the magnetic sensitivity and spin coherence properties.Moreover,the incident angle of energetic ions is found to influence both the depth and density distributions of the V_(B)^(-)ensemble,a factor that is often overlooked.These results pave the way for improving the performance of quantum sensors based on hBN spin defects by optimizing the irradiation parameters.展开更多
Recently, the rapid progress of quantum sensing research reveals that Rydberg atoms have great potential in becoming high-precision centimeter-scale antennas for low-frequency fields. In order to facilitate efficient ...Recently, the rapid progress of quantum sensing research reveals that Rydberg atoms have great potential in becoming high-precision centimeter-scale antennas for low-frequency fields. In order to facilitate efficient and reliable detection of low-frequency fields via Rydberg atoms, we designed and implemented a heterodyne method based on the linear response to external signals under the condition of Rydberg electromagnetically induced transparency(EIT). Instead of relying on observing changes in the absorption of light by Rydberg atoms, our method focuses on the phase modulation effect on the probe laser induced by low-frequency fields via the Rydberg EIT mechanism and utilizes a special demodulation process to accurately retrieve signals including both amplitude and phase. The general principles of our method apply to both electric and magnetic fields, and it is even possible to realize a combination of both functionalities in the same apparatus. In particular, we experimentally demonstrate the full cycle of operations with respect to both cases. In measuring low-frequency electric fields,we discover that the Rydberg dipole–dipole interaction among atoms induces a linear superposition of Rydberg states with different angular momentum, generating a first-order response corresponding to the signature of the linear Stark effect. As Rydberg atoms have excellent coupling strengths with electric fields, our results indicate that our method can hopefully achieve high-precision performance for practical tasks in the future.展开更多
Exploring the quantum advantages of various non-classical quantum states in noisy environments is a central subject in quantum sensing.Here we provide a complete picture for the frequency estimation precision of three...Exploring the quantum advantages of various non-classical quantum states in noisy environments is a central subject in quantum sensing.Here we provide a complete picture for the frequency estimation precision of three important states(the Greenberger-Horne-Zeilinger(GHZ)state,the maximal spin squeezed state,and the spin coherent state)of a spin-S under both individual dephasing and collective dephasing by general Gaussian noise,ranging from the Markovian limit to the extreme non-Markovian limit.Whether or not the noise is Markovian,the spin coherent state is always worse than the classical scheme under collective dephasing although it is equivalent to the classical scheme under individual dephasing.Moreover,the maximal spin squeezed state always give the best sensing precision(and outperforms the widely studied GHZ state)in all cases.This establishes the general advantage of the spin squeezed state for noisy frequency estimation in many quantum sensing platforms.展开更多
Dynamical decoupling(DD),usually implemented by sophisticated sequences of instantaneous control pulses,is a well-established quantum control technique for quantum information and quantum sensing.In practice,the pulse...Dynamical decoupling(DD),usually implemented by sophisticated sequences of instantaneous control pulses,is a well-established quantum control technique for quantum information and quantum sensing.In practice,the pulses are inevitably imperfect with many systematic errors that may influence the performances of DD.In particular,Rabi error and detuning are primary systemic errors arising from finite pulse duration,incorrect time control,and frequency instability.Here,we propose a phase-modulated DD with staggered global phases for the basic units of the pulse sequences to suppress these systemic errors.By varying the global phases appended to the pulses in the dynamical decoupling unit alternatively with 0 orπ,our protocol can significantly reduce the influences of Rabi error and detuning.Our protocol is general and can be combined with the most existing DD sequences such as universal DD,knill DD,XY,etc.As an example,we further apply our method to quantum lock-in detection for measuring time-dependent alternating signals.Our study paves the way for a simple and feasible way to realize robust dynamical decoupling sequences,which can be applicable for various quantum sensing scenarios.展开更多
In this review,we address the emerging field of quantum photonic sensing leveraging the polarization degree of freedom.We briefly discuss the main aspects of treating polarization in quantum optics,and provide an over...In this review,we address the emerging field of quantum photonic sensing leveraging the polarization degree of freedom.We briefly discuss the main aspects of treating polarization in quantum optics,and provide an overview of the main trends in the development of the field and the strategies to realize quantum-enhanced polarization-based sensing as well as a comprehensive survey of the main advancements in the field.We aim at promoting quantum approaches to the researchers in classical optical polarimetry as well as underscoring the sustainability and resourcefulness of the field for prospective applications and attracting the researchers in quantum optics to this new emerging field.展开更多
The integration of sensing and communication can achieve ubiquitous sensing while enabling ubiquitous communication.Within the gradually improving global communication,the integrated sensing and communication system b...The integration of sensing and communication can achieve ubiquitous sensing while enabling ubiquitous communication.Within the gradually improving global communication,the integrated sensing and communication system based on optical fibers can accomplish various functionalities,such as urban structure imaging,seismic wave detection,and pipeline safety monitoring.With the development of quantum communication,quantum networks based on optical fiber are gradually being established.In this paper,we propose an integrated sensing and quantum network(ISAQN)scheme,which can achieve secure key distribution among multiple nodes and distributed sensing under the standard quantum limit.The continuous variables quantum key distribution protocol and the round-trip multiband structure are adopted to achieve the multinode secure key distribution.Meanwhile,the spectrum phase monitoring protocol is proposed to realize distributed sensing.It determines which node is vibrating by monitoring the frequency spectrum and restores the vibration waveform by monitoring the phase change.The scheme is experimentally demonstrated by simulating the vibration in a star structure network.Experimental results indicate that this multiuser quantum network can achieve a secret key rate of approximately 0.7 Mbits/s for each user under 10-km standard fiber transmission,and its network capacity is 8.In terms of distributed sensing,it can achieve a vibration response bandwidth ranging from 1 Hz to 2 kHz,a strain resolution of 0.50 nε/Hz,and a spatial resolution of 0.20 m under shot-noise-limited detection.The proposed ISAQN scheme enables simultaneous quantum communication and distributed sensing in a multipoint network,laying a foundation for future large-scale quantum networks and high-precision sensing networks.展开更多
Dynamical decoupling(DD)is normally ineffective when applied to DC measurement.In its straightforward implementation,DD nulls out DC signal as well while suppressing noise.This work proposes a phase relay method that ...Dynamical decoupling(DD)is normally ineffective when applied to DC measurement.In its straightforward implementation,DD nulls out DC signal as well while suppressing noise.This work proposes a phase relay method that is capable of continuously interrogating the DC signal over many DD cycles.We illustrate its efficacy when applied to the measurement of a weak DC magnetic field with an atomic spinor Bose-Einstein condensate.Sensitivities approaching standard quantum limit or Heisenberg limit are potentially realizable for a coherent spin state or a squeezed spin state of 10000 atoms,respectively,while ambient laboratory level noise is suppressed by DD.Our work offers a practical approach to mitigate the limitations of DD to DC measurement and would find other applications for resorting coherence in quantum sensing and quantum information processing research.展开更多
Existing microfabricated atomic vapor cells have only one optical channel,which is insufficient for supporting the multiple orthogonal beams required by atomic devices.In this study,we present a novel wafer-level manu...Existing microfabricated atomic vapor cells have only one optical channel,which is insufficient for supporting the multiple orthogonal beams required by atomic devices.In this study,we present a novel wafer-level manufacturing process for fabricating multi-optical-channel atomic vapor cells and an innovative method for batch processing the inner sidewalls of millimeter glass holes to meet optical channel requirements.Surface characterization and transmittance tests demonstrate that the processed inner sidewalls satisfy the criteria for an optical channel.In addition,the construction of an integrated processing platform enables multilayer non-isothermal anode bonding,the filling of inert gases,and the recovery and recycling of noble gases.Measurements of the absorption spectra and free-induction decay signals of xenon-129(^(129)Xe)and xenon-131(^(131)Xe)under different pump-probe schemes demonstrate the suitability of our vapor cell for use in atomic devices including atomic gyroscopes,dual-beam atomic magnetometers,and other optical/atomic devices.The proposed micromolding technology has broad application prospects in the field of optical-device processing.展开更多
Nitrogen-vacancy(NV)centers in a bulk diamond are often employed to realize measurement of multiple physical quantities,which depends on orientation information of NV axis.We report a fast and effective method to dete...Nitrogen-vacancy(NV)centers in a bulk diamond are often employed to realize measurement of multiple physical quantities,which depends on orientation information of NV axis.We report a fast and effective method to determine the orientation of NV axis with the aid of a static magnetic field.By measuring the optically detected magnetic resonance spectra,we can precisely extract the polar angle information between the NV axis and the known magnetic field.Combining with the polar angle information of different kinds of NV centers,we employ the Nelder-Mead algorithm to get the optimal solution of the orientation of NV axis.This method is simple and efficient,and is easily applied in NV-based quantum sensing.展开更多
Quantum states are essential resource for quantum-enhanced applications.Loss incurred in the distribution channel,however,dissipates the high signal-to-noise ratio advantage enjoyed by the squeezed state.Here,we first...Quantum states are essential resource for quantum-enhanced applications.Loss incurred in the distribution channel,however,dissipates the high signal-to-noise ratio advantage enjoyed by the squeezed state.Here,we first demonstrate noise immunity enhancement by using phase-sensitive amplifier(PSA)with measurement-based noiseless linear amplifier(MB-NLA).We explore the signal transfer capability with the amplifier in a noisy channel.The MB-NLA enhanced PSA has obvious suppression effect on channel noises,especially it has improvement for the noise contaminated signal.Better performance can be achieved by flexibly adjusting amplifier parameters.With the amplifier,it is promising to overcome the entanglement-distribution loss and show its superiority in squeezing based quantum sensing.展开更多
基金supported by the National Natural Science Foun-dation of China(Grant No.92165107)the China Postdoctoral Science Foundation(Grant No.2022M723270)the National Defense Basic Scientific Research Pogram of China。
文摘Isotropic laser cooling(ILC)is widely recognized for its distinct advantages and demonstrates significant potential in quantum precision measurements and quantum sensing technologies.The morphology and density distribution of the cold atomic cloud generated by ILC are strongly influenced by the distribution of cooling light and the structural geometry of the cavity,making precise characterization and optimization of cold atom distribution essential for practical applications.In this paper,we present an innovative flat diffuse cavity design with the dimensions approximating a quasi-two-dimensional configuration,which generates a sheet-like isotropic laser field inside the cavity through diffuse reflections.We thoroughly characterized the system’s performance under different optical parameter settings.A two-dimensional(2D)movable detection system was employed to detect the quasi-two-dimensional distribution of cold atoms.These results demonstrate the ability of ILC to produce diverse morphological and density distributions of cold atoms,which we anticipate will be suitable for quantum sensing.
基金Project supported by the National Natural Science Foundation of China(Grant No.11974336)the National Key Research and Development Program of China(Grant No.2017YFA0304100)
文摘Single-electron spins in quantum dots are the leading platform for qubits,while magnons in solids are one of the emerging candidates for quantum technologies.How to manipulate a composite system composed of both systems is an outstanding challenge.Here,we use spin-charge hybridization to effectively couple the single-electron spin state in quantum dots to the cavity and further to the magnons.Through this coupling,quantum dots can entangle and detect magnon states.The detection efficiency can reach 0.94 in a realistic experimental situation.We also demonstrate the electrical tunability of the scheme for various parameters.These results pave a practical pathway for applications of composite systems based on quantum dots and magnons.
文摘The accuracy of power system measurements directly affects the safe and stable operation of power grids. This study explores the application prospects of quantum sensing technology in power system measurements. The research first analyzes the limitations of traditional measurement techniques, such as electromagnetic interference sensitivity and measurement accuracy bottlenecks. It then introduces the basic principles of quantum sensing, including concepts like quantum entanglement and superposition states. Through theoretical analysis and numerical simulations, the study assesses the potential advantages of quantum sensors in current, voltage, and magnetic field measurements. Results show that quantum magnetometers offer significant improvements in accuracy and interference resistance for current measurements. The study also discusses the application of quantum optical technology in high-voltage measurements, demonstrating its unique advantages in improving measurement dynamic range. However, quantum sensing technology still faces challenges in practical applications, such as technological maturity and cost. To address these issues, the research proposes a phased implementation strategy and industry-academia collaboration model. Finally, the study envisions future directions combining quantum sensing with artificial intelligence. This research provides a theoretical foundation for innovative upgrades in power system measurement technology.
文摘Error correction has long been suggested to extend the sensitivity of quantum sensors into the Heisenberg Limit. However, operations on logical qubits are only performed through universal gate sets consisting of finite-sized gates such as Clifford + T. Although these logical gate sets allow for universal quantum computation, the finite gate sizes present a problem for quantum sensing, since in sensing protocols, such as the Ramsey measurement protocol, the signal must act continuously. The difficulty in constructing a continuous logical op-erator comes from the Eastin-Knill theorem, which prevents a continuous sig-nal from being both fault-tolerant to local errors and transverse. Since error correction is needed to approach the Heisenberg Limit in a noisy environment, it is important to explore how to construct fault-tolerant continuous operators. In this paper, a protocol to design continuous logical z-rotations is proposed and applied to the Steane Code. The fault tolerance of the designed operator is investigated using the Knill-Laflamme conditions. The Knill-Laflamme condi-tions indicate that the diagonal unitary operator constructed cannot be fault tolerant solely due to the possibilities of X errors on the middle qubit. The ap-proach demonstrated throughout this paper may, however, find success in codes with more qubits such as the Shor code, distance 3 surface code, [15, 1, 3] code, or codes with a larger distance such as the [11, 1, 5] code.
基金supported by National Natural Science Foundation of China(Grant No.12175150)the Natural Science Foundation of Guang-dong Province(Grant No.2019A1515011400)。
文摘This work theoretically studies the Bose–Hubbard(BH)model in a ring geometry in a rotating frame.We obtain an effective Hamiltonian by using unitary transformation,where the effect of the rotating reference frame is introducing additional phases to the hopping constant.Within the mean-field theory,the phase transition edge depends not only on the particle number and ring radius,but also on rotation velocity.Therefore,we propose a sensing method of the rotation velocity using the phase transition edge of the Bose–Hubbard model.At the exact phase transition edge where this sensing method is most sensitive,the resolution depends on the rotation velocity,the particle number and the ring radius,while it is independent of the parameters in the Bose–Hubbard model such as the hopping constant and the on-site interaction.
基金supported by the National Key R&D Program of China(Grant No.2022YFF0712800)Innova-tion Program for Quantum Science and Technology(Grant No.2021ZD0301500).
文摘A maximal photon number entangled state,namely NOON state,can be adopted for sensing with a quantum enhancedprecision.In this work,we designed silicon quantum photonic chips containing two types of Mach-Zehnder interferometerswherein the two-photon NOON state,sensing element for temperature or humidity,is generated.Compared with classicallight or single photon case,two-photon NOON state sensing shows a solid enhancement in the sensing resolution andprecision.As the first demonstration of on-chip quantum photonic sensing,it reveals the advantages of photonic chips forhigh integration density,small-size,stability for multiple-parameter sensing serviceability.A higher sensing precision isexpected to beat the standard quantum limit with a higher photon number NOON state.
基金supported by the National Natural Science Foundation of China(Grant Nos.12274080,11874114,and 11875108)the National Youth Science Foundation of China(Grant No.12204105)+1 种基金the Educational Research Project for Young and Middle-aged Teachers of Fujian Province(Grant No.JAT210041)the Natural Science Foundation of Fujian Province(Grant Nos.2021J01574,and 2022J05116).
文摘Quantum systems that undergo quantum phase transitions exhibit divergent susceptibility and can be exploited as probes to estimate physical parameters.We generalize the dynamic framework for criticality-enhanced quantum sensing by the quantum Rabi model(QRM)to its anisotropic counterpart and derive the correspondingly analytical expressions for the quantum Fisher information(QFI).We find that the contributions of the rotating-wave and counterrotating-wave interaction terms are symmetric at the limit of the infinite ratio of qubit frequency to field frequency,with the QFI reaching a maximum for the isotropic QRM.At finite frequency scaling,we analytically derive the inverted variance of higher-order correction and find that it is more affected by the rotating-wave coupling than by the counterrotating-wave coupling.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 11534002, U1930402, and U1930403).
文摘Quantum sensing has been receiving researcher's attention these years due to its ultrahigh sensitivity and precision. However, the bandwidth of the sensors may be low, thus limiting the scope of their practical applications. The low-bandwidth problem is conquered by feedback control methods, which are widely utilized in classic control fields. Based on a quantum harmonic oscillator model operating near the resonant point, the bandwidth and sensitivity of the quantum sensor are analyzed. The results give two important conclusions: (a) the bandwidth and sensitivity are two incompatible performance parameters of the sensor, so there must be a trade-off between bandwidth and sensitivity in practical applications;(b) the quantum white noise affects the signal to be detected in a non-white form due to the feedback control.
文摘Quantum technologies,mainly quantum computing and quantum sensing are emerging as new applications of quantum mechanics for practical use.Two notable advancements in quantum computing and quantum sensing respectively are Shor’s algorithm and nitrogen vacancy centers in diamond lattices.Shor’s algorithm leverages certain properties of quantum computers to factor large numbers faster than any classical algorithm.Nitrogen vacancy centers leverage spin defects to sense even very small signatures of magnetic fields.This review article aims to provide a pedagogical introduction and overview of these emerging platforms for quantum technology.
文摘Optically detected magnetic resonance(ODMR)has emerged as a powerful technique for quantum sensing,enabling high-sensitivity detection of physical quantities even at room temperature.Solid-state defects,such as nitrogen-vacancy(NV)centers in diamond,have demonstrated remarkable capabilities in this domain[1–4].However,these systems are limited by their rigid lattice structures and lack tunability.
基金supported by the National Key Research and Development Program Project(2024YFF0726104)Key Laboratory of Modern Optical Technologies of the Education Ministry of China,Soochow University(Grant No.KJS2135)+1 种基金a China Postdoctoral Science Foundation Funded Project(Grant No.2024M751236)the Jiangxi Provincial Natural Science Foundation(Grant No.20232BAB211030).
文摘Negatively charged boron vacancy(V_(B)^(-))spin defects are stable in nanoscale hexagonal boron nitride(hBN)flakes,which can be easily integrated into two-dimensional materials and devices to serve as both sensors and protective materials.Ion irradiation is frequently employed to create V_(B)^(-)spin defects in hBN.However,the optimal ion irradiation parameters remain unclear,even though they play a crucial role in determining the depth and density of the defects,which in turn affect sensing sensitivity.In this work,we optimize the carbon ion irradiation parameters for creating V_(B)^(-)spin defects by varying the irradiation dose and the incident angle.For 30 keV carbon ion irradiation,the optimal irradiation dose to create a V_(B)^(-)ensemble is determined to be 4×10^(13)ions/cm^(2),and both continuous and pulsed optically detected magnetic resonance measurements are used to estimate the magnetic sensitivity and spin coherence properties.Moreover,the incident angle of energetic ions is found to influence both the depth and density distributions of the V_(B)^(-)ensemble,a factor that is often overlooked.These results pave the way for improving the performance of quantum sensors based on hBN spin defects by optimizing the irradiation parameters.
基金supported by the Science and Technology Commission of Shanghai Municipality (Grant No.24DP2600202)the National Key R&D Program of China (Grant No.2024YFB4504002)+2 种基金Industrial Technology Development Research Program of Shanghai Institute of Optics and Fine Mechanicsthe National Natural Science Foundation of China (Grant No.92165107)the China Postdoctoral Science Foundation (Grant Nos.2024M753359 for S.J.and2022M723270 for X.W.)。
文摘Recently, the rapid progress of quantum sensing research reveals that Rydberg atoms have great potential in becoming high-precision centimeter-scale antennas for low-frequency fields. In order to facilitate efficient and reliable detection of low-frequency fields via Rydberg atoms, we designed and implemented a heterodyne method based on the linear response to external signals under the condition of Rydberg electromagnetically induced transparency(EIT). Instead of relying on observing changes in the absorption of light by Rydberg atoms, our method focuses on the phase modulation effect on the probe laser induced by low-frequency fields via the Rydberg EIT mechanism and utilizes a special demodulation process to accurately retrieve signals including both amplitude and phase. The general principles of our method apply to both electric and magnetic fields, and it is even possible to realize a combination of both functionalities in the same apparatus. In particular, we experimentally demonstrate the full cycle of operations with respect to both cases. In measuring low-frequency electric fields,we discover that the Rydberg dipole–dipole interaction among atoms induces a linear superposition of Rydberg states with different angular momentum, generating a first-order response corresponding to the signature of the linear Stark effect. As Rydberg atoms have excellent coupling strengths with electric fields, our results indicate that our method can hopefully achieve high-precision performance for practical tasks in the future.
基金supported by the National Natural Science Foundation of China(NSFC)Grant No.12274019the NSAF grant in NSFC with Grant No.U2230402。
文摘Exploring the quantum advantages of various non-classical quantum states in noisy environments is a central subject in quantum sensing.Here we provide a complete picture for the frequency estimation precision of three important states(the Greenberger-Horne-Zeilinger(GHZ)state,the maximal spin squeezed state,and the spin coherent state)of a spin-S under both individual dephasing and collective dephasing by general Gaussian noise,ranging from the Markovian limit to the extreme non-Markovian limit.Whether or not the noise is Markovian,the spin coherent state is always worse than the classical scheme under collective dephasing although it is equivalent to the classical scheme under individual dephasing.Moreover,the maximal spin squeezed state always give the best sensing precision(and outperforms the widely studied GHZ state)in all cases.This establishes the general advantage of the spin squeezed state for noisy frequency estimation in many quantum sensing platforms.
基金Project supported by the National Key Research and Development Program of China(Grant No.2022YFA1404104)the National Natural Science Foundation of China(Grant Nos.92476201,12025509,12305022,and 12475029)+1 种基金the Key-Area Research and Development Program of Guangdong Province,China(Grant No.2019B030330001)Guangdong Provincial Quantum Science Strategic Initiative Fund(Grant Nos.GDZX2305006 and GDZX2405002)。
文摘Dynamical decoupling(DD),usually implemented by sophisticated sequences of instantaneous control pulses,is a well-established quantum control technique for quantum information and quantum sensing.In practice,the pulses are inevitably imperfect with many systematic errors that may influence the performances of DD.In particular,Rabi error and detuning are primary systemic errors arising from finite pulse duration,incorrect time control,and frequency instability.Here,we propose a phase-modulated DD with staggered global phases for the basic units of the pulse sequences to suppress these systemic errors.By varying the global phases appended to the pulses in the dynamical decoupling unit alternatively with 0 orπ,our protocol can significantly reduce the influences of Rabi error and detuning.Our protocol is general and can be combined with the most existing DD sequences such as universal DD,knill DD,XY,etc.As an example,we further apply our method to quantum lock-in detection for measuring time-dependent alternating signals.Our study paves the way for a simple and feasible way to realize robust dynamical decoupling sequences,which can be applicable for various quantum sensing scenarios.
基金support from the German Federal Ministry of Education and Research(BMBF,Projekt QUANCER-FKZ13N16441)the China Scholarship Council(No.201904910805)for funding and initiating the PhD exchange programthe Pro Chancecareer program of the Friedrich Schiller University Jena for funding this work。
文摘In this review,we address the emerging field of quantum photonic sensing leveraging the polarization degree of freedom.We briefly discuss the main aspects of treating polarization in quantum optics,and provide an overview of the main trends in the development of the field and the strategies to realize quantum-enhanced polarization-based sensing as well as a comprehensive survey of the main advancements in the field.We aim at promoting quantum approaches to the researchers in classical optical polarimetry as well as underscoring the sustainability and resourcefulness of the field for prospective applications and attracting the researchers in quantum optics to this new emerging field.
基金supported by Innovation Program for Quantum Science and Technology(Grant No.2021ZD0300703)the National Natural Science Foundation of China(Grant No.62101320)+1 种基金the Shanghai Municipal Science and Technology Major Project(Grant No.2019SHZDZX01)the Hebei Provincial Science and Technology Project(Grant No.22310701D).
文摘The integration of sensing and communication can achieve ubiquitous sensing while enabling ubiquitous communication.Within the gradually improving global communication,the integrated sensing and communication system based on optical fibers can accomplish various functionalities,such as urban structure imaging,seismic wave detection,and pipeline safety monitoring.With the development of quantum communication,quantum networks based on optical fiber are gradually being established.In this paper,we propose an integrated sensing and quantum network(ISAQN)scheme,which can achieve secure key distribution among multiple nodes and distributed sensing under the standard quantum limit.The continuous variables quantum key distribution protocol and the round-trip multiband structure are adopted to achieve the multinode secure key distribution.Meanwhile,the spectrum phase monitoring protocol is proposed to realize distributed sensing.It determines which node is vibrating by monitoring the frequency spectrum and restores the vibration waveform by monitoring the phase change.The scheme is experimentally demonstrated by simulating the vibration in a star structure network.Experimental results indicate that this multiuser quantum network can achieve a secret key rate of approximately 0.7 Mbits/s for each user under 10-km standard fiber transmission,and its network capacity is 8.In terms of distributed sensing,it can achieve a vibration response bandwidth ranging from 1 Hz to 2 kHz,a strain resolution of 0.50 nε/Hz,and a spatial resolution of 0.20 m under shot-noise-limited detection.The proposed ISAQN scheme enables simultaneous quantum communication and distributed sensing in a multipoint network,laying a foundation for future large-scale quantum networks and high-precision sensing networks.
基金Project supported by the NSAF(Grant No.U1930201)the National Natural Science Foundation of China(Grant Nos.12274331,91836101,and 91836302)+1 种基金the National Key R&D Program of China(Grant No.2018YFA0306504)Innovation Program for Quantum Science and Technology(Grant No.2021ZD0302100).
文摘Dynamical decoupling(DD)is normally ineffective when applied to DC measurement.In its straightforward implementation,DD nulls out DC signal as well while suppressing noise.This work proposes a phase relay method that is capable of continuously interrogating the DC signal over many DD cycles.We illustrate its efficacy when applied to the measurement of a weak DC magnetic field with an atomic spinor Bose-Einstein condensate.Sensitivities approaching standard quantum limit or Heisenberg limit are potentially realizable for a coherent spin state or a squeezed spin state of 10000 atoms,respectively,while ambient laboratory level noise is suppressed by DD.Our work offers a practical approach to mitigate the limitations of DD to DC measurement and would find other applications for resorting coherence in quantum sensing and quantum information processing research.
基金supported in part by the National Key Research and Development Plan(2022YFB3203400)the National Natural Science Foundation of China(62103324 and U1909221)the Natural Science Foundation of Shaanxi(2022JQ-554).
文摘Existing microfabricated atomic vapor cells have only one optical channel,which is insufficient for supporting the multiple orthogonal beams required by atomic devices.In this study,we present a novel wafer-level manufacturing process for fabricating multi-optical-channel atomic vapor cells and an innovative method for batch processing the inner sidewalls of millimeter glass holes to meet optical channel requirements.Surface characterization and transmittance tests demonstrate that the processed inner sidewalls satisfy the criteria for an optical channel.In addition,the construction of an integrated processing platform enables multilayer non-isothermal anode bonding,the filling of inert gases,and the recovery and recycling of noble gases.Measurements of the absorption spectra and free-induction decay signals of xenon-129(^(129)Xe)and xenon-131(^(131)Xe)under different pump-probe schemes demonstrate the suitability of our vapor cell for use in atomic devices including atomic gyroscopes,dual-beam atomic magnetometers,and other optical/atomic devices.The proposed micromolding technology has broad application prospects in the field of optical-device processing.
基金This work was supported by the National Key R&D Program of China(Grant No.2020YFA0309400)the National Natural Science Foundation of China(Grant No.12174081)the Fundamental Research Funds for the Central Universities(Grant Nos.JZ2021HGTB0126 and PA2021KCPY0052).
文摘Nitrogen-vacancy(NV)centers in a bulk diamond are often employed to realize measurement of multiple physical quantities,which depends on orientation information of NV axis.We report a fast and effective method to determine the orientation of NV axis with the aid of a static magnetic field.By measuring the optically detected magnetic resonance spectra,we can precisely extract the polar angle information between the NV axis and the known magnetic field.Combining with the polar angle information of different kinds of NV centers,we employ the Nelder-Mead algorithm to get the optimal solution of the orientation of NV axis.This method is simple and efficient,and is easily applied in NV-based quantum sensing.
基金the National Natural Science Foundation of China(Grant No.12074233)the National Key Research and Development Program of China(Grant No.2021YFC2201802)Shanxi(1331 Project)。
文摘Quantum states are essential resource for quantum-enhanced applications.Loss incurred in the distribution channel,however,dissipates the high signal-to-noise ratio advantage enjoyed by the squeezed state.Here,we first demonstrate noise immunity enhancement by using phase-sensitive amplifier(PSA)with measurement-based noiseless linear amplifier(MB-NLA).We explore the signal transfer capability with the amplifier in a noisy channel.The MB-NLA enhanced PSA has obvious suppression effect on channel noises,especially it has improvement for the noise contaminated signal.Better performance can be achieved by flexibly adjusting amplifier parameters.With the amplifier,it is promising to overcome the entanglement-distribution loss and show its superiority in squeezing based quantum sensing.
