Cold trapped ions can be excellent sensors for ultra-precision detection of physical quantities,which strongly depends on the measurement situation at hand.The stylus ion trap,formed by two concentric cylinders over a...Cold trapped ions can be excellent sensors for ultra-precision detection of physical quantities,which strongly depends on the measurement situation at hand.The stylus ion trap,formed by two concentric cylinders over a ground plane,holds the promise of relatively simple structure and larger solid angle for optical access and fluorescence collection in comparison with the conventional ion traps.Here we report our fabrication and characterization of the first stylus ion trap constructed in China,aiming for studying quantum optics and sensing weak electric fields in the future.We have observed the stable confinement of the ion in the trapping potential for more than two hours and measured the heating rate of the trap to be dε/dt=7.10±0.13 meV/s by the Doppler recooling method.Our work starts a way to building practical quantum sensors with high efficiency of optical collection and with ultimate goal for contributing to future quantum information technology.展开更多
Time synchronization and phase shaping of single photons both play fundamental roles in quantum information applications that rely on multi-photon quantum interference.Phase shaping typically requires separate modulat...Time synchronization and phase shaping of single photons both play fundamental roles in quantum information applications that rely on multi-photon quantum interference.Phase shaping typically requires separate modulators with extra insertion losses.Here,we develop an all-optical built-in phase modulator for single photons using a quantum memory.The fast phase modulation of a single photon in both step and linear manner are verified by observing the efficient quantum-memory-assisted Hong-Ou-Mandel interference between two single photons,where the anti-coalescence effect of bosonic photon pairs is demonstrated.The developed phase modulator may push forward the practical quantum information applications.展开更多
Stochastic resonance is a counterintuitive phenomenon amplifying the weak periodic signal by application of external noise.We demonstrate the enhancement of a weak periodic signal by stochastic resonance in a trappedi...Stochastic resonance is a counterintuitive phenomenon amplifying the weak periodic signal by application of external noise.We demonstrate the enhancement of a weak periodic signal by stochastic resonance in a trappedion oscillator when the oscillator is excited to the nonlinear regime and subject to an appropriate noise.Under the full control of the radio-frequency drive voltage,this amplification originates from the nonlinearity due to asymmetry of the trapping potential,which can be described by a forced Duffing oscillator model.Our scheme and results provide an interesting possibility to make use of controllable nonlinearity in the trapped ion,and pave the way toward a practical atomic sensor for sensitively detecting weak periodic signals from real noisy environment.展开更多
We analytically and numerically investigate the dynamical properties of the tilted dispersion relativistic quasiparticles emerged in a cold atomic optical lattice system.By introducing the next nearest neighboring(NNN...We analytically and numerically investigate the dynamical properties of the tilted dispersion relativistic quasiparticles emerged in a cold atomic optical lattice system.By introducing the next nearest neighboring(NNN)hopping term into Su-Schrieffer-Heeger(SSH)model,the Dirac quasiparticles with tilted dispersion relation are realized.The results show that the tilted dispersion causes a drift in relativistic quasiparticles rather than affecting interference behavior between inner states.To be specific,the relativistic phenomena of the quasiparticles induced by the inner state interference(such as Zitterbewegung,Klein paradox,etc.)is completely unaffected by the tilted dispersion.In order to distinguish the drift induced by tilted dispersion and common initial velocity,we calculate the momentum distribution of the relativistic quasiparticles.We obtain the difference between the drift induced by initial velocity and tilted dispersion.The former affects the ZB,while the latter does not.By using this character,we propose a quench dynamics scheme to obtain a stable mono-spin state.The proposed cold atomic lattice system would provide a promising platform in exploring the intrinsic exotic physics of relativistic quasiparticles and the related systems.展开更多
We achieve the robust nonadiabatic holonomic two-qubit controlled gate in one step based on the groundstate blockade mechanism between two Rydberg atoms. By using the Rydberg-blockade effect and the Raman transition m...We achieve the robust nonadiabatic holonomic two-qubit controlled gate in one step based on the groundstate blockade mechanism between two Rydberg atoms. By using the Rydberg-blockade effect and the Raman transition mechanism, we can produce the blockade effect of double occupation of the corresponding ground state,i.e., ground-state blockade, to encode the computational subspace into the ground state, thus effectively avoiding the spontaneous emission of the excited Rydberg state. On the other hand, the feature of geometric quantum computation independent of the evolutionary details makes the scheme robust to control errors. In this way,the controlled quantum gate constructed by our scheme not only greatly reduces the gate infidelity caused by spontaneous emission but is also robust to control errors.展开更多
Detecting extremely small forces helps exploring new physics quantitatively.Here we demonstrate that the phonon laser made of a single trapped ^(40)Ca^(+) ion behaves as an exquisite sensor for small force measurement...Detecting extremely small forces helps exploring new physics quantitatively.Here we demonstrate that the phonon laser made of a single trapped ^(40)Ca^(+) ion behaves as an exquisite sensor for small force measurement.We report our successful detection of small electric forces regarding the DC trapping potential with sensitivity of(2.41±0.49)zN/√Hz,with the ion only under Doppler cooling,based on the injection-locking of the oscillation phase of the phonon laser in addition to the classical squeezing applied to suppress the measurement uncertainty.We anticipate that such a single-ion sensor would reach a much better force detection sensitivity in the future once the trapping system is further improved and the fluorescence collection efficiency is further enhanced.展开更多
Applying a three-band model and the random phase approximation,we theoretically study the spin excitations in nickelate superconductors,which have been newly discovered.The spin excitations were found to be incommensu...Applying a three-band model and the random phase approximation,we theoretically study the spin excitations in nickelate superconductors,which have been newly discovered.The spin excitations were found to be incommensurate in the low energy region.The spin resonance phenomenon emerged as the excitation energy increased.The intensity can be maximized at the incommensurate or commensurate momentum,depending on the out-of-plane momentum.The spin excitations reverted to incommensurate at higher energies.We also discuss the similarities and differences in the spin excitations of nickelate and cuprate superconductors.Our predicted results can be later validated in inelastic neutron scattering experiments.展开更多
基金Project supported by the Special Project for Research and Development in Key Areas of Guangdong Province,China (Grant No.2020B0303300001)the National Natural Science Foundation of China (Grant Nos.U21A20434,12074346,12074390,11835011,11804375,and 11804308)+2 种基金the Fund from the Key Laboratory of Guangzhou for Quantum Precision Measurement (Grant No.202201000010)the Science and Technology Projects in Guangzhou (Grant No.202201011727)the Nansha Senior Leading Talent Team Technology Project (Grant No.2021CXTD02)。
文摘Cold trapped ions can be excellent sensors for ultra-precision detection of physical quantities,which strongly depends on the measurement situation at hand.The stylus ion trap,formed by two concentric cylinders over a ground plane,holds the promise of relatively simple structure and larger solid angle for optical access and fluorescence collection in comparison with the conventional ion traps.Here we report our fabrication and characterization of the first stylus ion trap constructed in China,aiming for studying quantum optics and sensing weak electric fields in the future.We have observed the stable confinement of the ion in the trapping potential for more than two hours and measured the heating rate of the trap to be dε/dt=7.10±0.13 meV/s by the Doppler recooling method.Our work starts a way to building practical quantum sensors with high efficiency of optical collection and with ultimate goal for contributing to future quantum information technology.
基金Supported by the National Key Research and Development Program of China(Grant No.2020YFA0309500)the Key-Area Research and Development Program of Guangdong Province(Grant No.2019B030330001)+5 种基金the Key Project of Science and Technology of Guangzhou(Grant No.2019050001)the National Natural Science Foundation of China(Grant Nos.11822403,62005082,12004120,U20A2074U1801661)the Natural Science Foundation of Guangdong Province(Grant No.2018A0303130066)the China Postdoctoral Science Foundation(Grant No.2020M672681)the Guangdong Basic and Applied Basic Research Foundation(Grant No.2020A1515110848)。
文摘Time synchronization and phase shaping of single photons both play fundamental roles in quantum information applications that rely on multi-photon quantum interference.Phase shaping typically requires separate modulators with extra insertion losses.Here,we develop an all-optical built-in phase modulator for single photons using a quantum memory.The fast phase modulation of a single photon in both step and linear manner are verified by observing the efficient quantum-memory-assisted Hong-Ou-Mandel interference between two single photons,where the anti-coalescence effect of bosonic photon pairs is demonstrated.The developed phase modulator may push forward the practical quantum information applications.
基金supported by the Special Project for Research and Development in Key Areas of Guangdong Province(Grant No.2020B0303300001)the National Natural Science Foundation of China(Grant Nos.U21A20434,12074346,12074390,11835011,11804375,11804308)the Key Laboratory of Guangzhou for Quantum Precision Measurement(Grant No.202201000010)。
文摘Stochastic resonance is a counterintuitive phenomenon amplifying the weak periodic signal by application of external noise.We demonstrate the enhancement of a weak periodic signal by stochastic resonance in a trappedion oscillator when the oscillator is excited to the nonlinear regime and subject to an appropriate noise.Under the full control of the radio-frequency drive voltage,this amplification originates from the nonlinearity due to asymmetry of the trapping potential,which can be described by a forced Duffing oscillator model.Our scheme and results provide an interesting possibility to make use of controllable nonlinearity in the trapped ion,and pave the way toward a practical atomic sensor for sensitively detecting weak periodic signals from real noisy environment.
基金Project supported by the National Key Research and Development Program of China(Grant Nos.2016YFA0301803 and 2016YFA0302800)the National Natural Science Foundation of China(Grant Nos.11604103,11704132,11822403,and 91636218),the NSAF,China(Grant Nos.U1801661 and U1830111)+4 种基金the PCSIRT,China(Grant No.IRT1243)the Natural Science Foundation of Guangdong Province,China(Grant Nos.2016A030313436,2018A030313322,and 2018A0303130066)the KPST of Guangzhou(Grant No.201804020055)China Postdoctoral Science Foundation(Grant No.2018M633063)the Startup Foundation of SCNU.
文摘We analytically and numerically investigate the dynamical properties of the tilted dispersion relativistic quasiparticles emerged in a cold atomic optical lattice system.By introducing the next nearest neighboring(NNN)hopping term into Su-Schrieffer-Heeger(SSH)model,the Dirac quasiparticles with tilted dispersion relation are realized.The results show that the tilted dispersion causes a drift in relativistic quasiparticles rather than affecting interference behavior between inner states.To be specific,the relativistic phenomena of the quasiparticles induced by the inner state interference(such as Zitterbewegung,Klein paradox,etc.)is completely unaffected by the tilted dispersion.In order to distinguish the drift induced by tilted dispersion and common initial velocity,we calculate the momentum distribution of the relativistic quasiparticles.We obtain the difference between the drift induced by initial velocity and tilted dispersion.The former affects the ZB,while the latter does not.By using this character,we propose a quench dynamics scheme to obtain a stable mono-spin state.The proposed cold atomic lattice system would provide a promising platform in exploring the intrinsic exotic physics of relativistic quasiparticles and the related systems.
基金supported by the Special Project for Research and Development in Key Areas of Guangdong Province(Grant No.2020B0303300001)the National Natural Science Foundation of China(Grant Nos.U21A20434 and 12074346)the Natural Science Foundation of Henan Province(Grant No.212300410085)。
文摘We achieve the robust nonadiabatic holonomic two-qubit controlled gate in one step based on the groundstate blockade mechanism between two Rydberg atoms. By using the Rydberg-blockade effect and the Raman transition mechanism, we can produce the blockade effect of double occupation of the corresponding ground state,i.e., ground-state blockade, to encode the computational subspace into the ground state, thus effectively avoiding the spontaneous emission of the excited Rydberg state. On the other hand, the feature of geometric quantum computation independent of the evolutionary details makes the scheme robust to control errors. In this way,the controlled quantum gate constructed by our scheme not only greatly reduces the gate infidelity caused by spontaneous emission but is also robust to control errors.
基金supported by the Special Project for Research and Development in Key Areas of Guangdong Province(Grant No.2020B0303300001)National Key Research&Development Program of China(Grant No.2017YFA0304503)National Natural Science Foundation of China(Grant Nos.U21A20434,12074390,11835011,and 11734018)。
文摘Detecting extremely small forces helps exploring new physics quantitatively.Here we demonstrate that the phonon laser made of a single trapped ^(40)Ca^(+) ion behaves as an exquisite sensor for small force measurement.We report our successful detection of small electric forces regarding the DC trapping potential with sensitivity of(2.41±0.49)zN/√Hz,with the ion only under Doppler cooling,based on the injection-locking of the oscillation phase of the phonon laser in addition to the classical squeezing applied to suppress the measurement uncertainty.We anticipate that such a single-ion sensor would reach a much better force detection sensitivity in the future once the trapping system is further improved and the fluorescence collection efficiency is further enhanced.
基金supported by the National Key Research and Development Program of China(Grant No.2016YFA0301800)the General Research Fund(GRF)(Grant Nos.HKU 173309/16P,and HKU173057/17P)the Collaborative Research Fund(CRF)(Grant No.C6005-17G)of Hong Kong。
文摘Applying a three-band model and the random phase approximation,we theoretically study the spin excitations in nickelate superconductors,which have been newly discovered.The spin excitations were found to be incommensurate in the low energy region.The spin resonance phenomenon emerged as the excitation energy increased.The intensity can be maximized at the incommensurate or commensurate momentum,depending on the out-of-plane momentum.The spin excitations reverted to incommensurate at higher energies.We also discuss the similarities and differences in the spin excitations of nickelate and cuprate superconductors.Our predicted results can be later validated in inelastic neutron scattering experiments.
