The dephasing time T_(2)is a fundamental parameter that characterizes the coherence of electronic states and electron-phonon interactions in condensed matter physics.Accurate measurement of T_(2)is essential for eluci...The dephasing time T_(2)is a fundamental parameter that characterizes the coherence of electronic states and electron-phonon interactions in condensed matter physics.Accurate measurement of T_(2)is essential for elucidating ultrafast electronic and phononic processes,which are crucial for the development of advanced electronic,optoelectronic,and quantum devices.However,due to the complexity of solid-state systems with their intricate band structures and strong many-body interactions,reconstructing T_(2)remains a long-term challenge for both condensed matter physics and optical science.In this work,we introduce a machine learning(ML)approach to retrieve T_(2)from the high-order harmonic generation(HHG)spectrum resulting from the interaction between a strong infrared(IR)laser pulse and solid-state material.The consistency between the experimental and reconstructed HHG spectra validates the efficiency of our scheme.Our ML method offers two key advantages:first,it does not require stringent experimental conditions,and second,the optimization process is fully automated and more reliable than empirical selection of dephasing time values.The ability of our method to reconstruct dephasing time from solid HHG spectra provides a powerful tool for probing the intrinsic properties of materials under extreme conditions.Besides,our method provides another significant advantage,which offers a direct approach to calculating the quantum tunneling time of carriers between different energy bands under light-induced excitation.展开更多
In broadband coherent anti-Stokes Raman scattering （CARS） spectroscopy with supercontinuum （SC）, the simultaneously detectable spectral coverage is limited by the spectral continuity and the simultaneity of variou...In broadband coherent anti-Stokes Raman scattering （CARS） spectroscopy with supercontinuum （SC）, the simultaneously detectable spectral coverage is limited by the spectral continuity and the simultaneity of various spectral components of SC in an enough bandwidth. By numerical simulations, the optimal experimental conditions for improving the SC are obtained. The broadband time-resolved CARS spectrography based on the SC with required temporal and spectral distributions is realised. The global molecular vibrational spectrum with well suppressed nonresonant background noise can be obtained in a single measurement. At the same time, the measurements of dephasing times of various molecular vibrational modes can be conveniently achieved from intensities of a sequence of time-resolved CARS signals. It will be more helpful to provide a complete picture of molecular vibrations, and to exhibit a potential to understand not only both the solvent dynamics and the solute-solvent interactions, but also the mechanisms of chemical reactions in the fields of biology, chemistry and material science.展开更多
We present theoretical results on the generation of short-wavelength vortex beams in semiconductors through their interaction with an intense Laguerre-Gauss(LG)beam,in the regime where nonperturbative high-order harmo...We present theoretical results on the generation of short-wavelength vortex beams in semiconductors through their interaction with an intense Laguerre-Gauss(LG)beam,in the regime where nonperturbative high-order harmonics are generated.Our approach leverages key aspects of the microscopic mechanism for high-order harmonic generation(HHG)in condensed matter,including the incorporation of dephasing time in the semiconductor Bloch equations(SBEs),the integration of the SBE model with the thin-slab model,and the application of experimentally validated scaling laws for different harmonic orders.For our simulations,we use a zinc oxide crystal interacting with an LG vortex beam characterized by a topological charge of I=1.Time-domain analysis reveals that this is a feasible route,by synthesizing several harmonics,toward the generation of twisted attosecond pulse trains.These findings contribute to advancing the understanding of solid-state media interacting with structured light.展开更多
The nitrogen-vacancy(NV)color center in diamond is a promising solid-state quantum system at room temperature.However,its sensitivity is limited by its low fluorescence collection efficiency,and its coherence time is ...The nitrogen-vacancy(NV)color center in diamond is a promising solid-state quantum system at room temperature.However,its sensitivity is limited by its low fluorescence collection efficiency,and its coherence time is limited by spin interference of impurity electrons around the NV color center.Here,we innovatively fabricated a one-dimensional photonic crystal on the surface of diamond,which greatly improved the fluorescence intensity of the NV color centers and increased the sensitivity of NV ensembles by a factor of 2.92.In addition,the laser reflected by the photonic crystal excites impurity electrons around the NV color centers,improving the electric field environment around the NV color centers,which exponentially prolongs the dephasing time(from 209 to841 ns),opening avenues for NV color-center ensemble sensors.展开更多
Based on single Cesium atoims trapped in a 1064 nm microscopic optical trap we have exhibited a single qubit encoded in the Cesium ＂clock states＂. The single qubit initialization, detection and the fast state rotati...Based on single Cesium atoims trapped in a 1064 nm microscopic optical trap we have exhibited a single qubit encoded in the Cesium ＂clock states＂. The single qubit initialization, detection and the fast state rotation with high efficiencies are demonstrated and this state manipulation is crucial for quantmn information processing. The ground ~ates Rabi flopping rate of 229.0 ± 0.6 kHz is realized hy a two-photon Raman process. A clock states dephasing time of 3.0 ± 0.7 ms is measured, while all irreversible homogeneous dephasing time of 124 ± 17 ms is achieved by using the spin-echo technique. This well-controlled single atom provides an ideal quantmn qubit and quantmn node for quantum information processing.展开更多
基金supported by the Fundamental Research Funds for the Central Universities(Grant No.GK202207012)QCYRCXM-2022-241+4 种基金the National Key Research and Development Program of China(Grant No.2022YFE0134200)the Natural Science Foundation of Jilin Province(Grant No.20220101016JC)the National Natural Science Foundation of China(Grant Nos.12374238,11934004,and 11974230)partial support from the National Natural Science Foundation of China(Grant No.12274470)the Natural Science Foundation of Hunan Province for Distinguished Young Scholars(Grant No.2022JJ10070)。
文摘The dephasing time T_(2)is a fundamental parameter that characterizes the coherence of electronic states and electron-phonon interactions in condensed matter physics.Accurate measurement of T_(2)is essential for elucidating ultrafast electronic and phononic processes,which are crucial for the development of advanced electronic,optoelectronic,and quantum devices.However,due to the complexity of solid-state systems with their intricate band structures and strong many-body interactions,reconstructing T_(2)remains a long-term challenge for both condensed matter physics and optical science.In this work,we introduce a machine learning(ML)approach to retrieve T_(2)from the high-order harmonic generation(HHG)spectrum resulting from the interaction between a strong infrared(IR)laser pulse and solid-state material.The consistency between the experimental and reconstructed HHG spectra validates the efficiency of our scheme.Our ML method offers two key advantages:first,it does not require stringent experimental conditions,and second,the optimization process is fully automated and more reliable than empirical selection of dephasing time values.The ability of our method to reconstruct dephasing time from solid HHG spectra provides a powerful tool for probing the intrinsic properties of materials under extreme conditions.Besides,our method provides another significant advantage,which offers a direct approach to calculating the quantum tunneling time of carriers between different energy bands under light-induced excitation.
基金Project supported by the National Natural Science Foundation of China(Grant No.60627003)the Foundation for Creative Team in Institution of Higher Education of Guangdong Province,China(Grant No.06CXTD009)
文摘In broadband coherent anti-Stokes Raman scattering （CARS） spectroscopy with supercontinuum （SC）, the simultaneously detectable spectral coverage is limited by the spectral continuity and the simultaneity of various spectral components of SC in an enough bandwidth. By numerical simulations, the optimal experimental conditions for improving the SC are obtained. The broadband time-resolved CARS spectrography based on the SC with required temporal and spectral distributions is realised. The global molecular vibrational spectrum with well suppressed nonresonant background noise can be obtained in a single measurement. At the same time, the measurements of dephasing times of various molecular vibrational modes can be conveniently achieved from intensities of a sequence of time-resolved CARS signals. It will be more helpful to provide a complete picture of molecular vibrations, and to exhibit a potential to understand not only both the solvent dynamics and the solute-solvent interactions, but also the mechanisms of chemical reactions in the fields of biology, chemistry and material science.
基金financial support from the National Key Research and Development Program of China(grant no.2023YFA1407100)Guangdong Province Science and Technology Major Project(Future functional materials under extreme conditions—2021B0301030005)+1 种基金the Guangdong Natural Science Foundation(General Program project no.2023A1-515010871)support by the U.S.Department of Energy,Offi ce of Science,Basic Energy Sciences,Chemical Sciences,Geosciences,and Biosciences Division through the AMOS program.
文摘We present theoretical results on the generation of short-wavelength vortex beams in semiconductors through their interaction with an intense Laguerre-Gauss(LG)beam,in the regime where nonperturbative high-order harmonics are generated.Our approach leverages key aspects of the microscopic mechanism for high-order harmonic generation(HHG)in condensed matter,including the incorporation of dephasing time in the semiconductor Bloch equations(SBEs),the integration of the SBE model with the thin-slab model,and the application of experimentally validated scaling laws for different harmonic orders.For our simulations,we use a zinc oxide crystal interacting with an LG vortex beam characterized by a topological charge of I=1.Time-domain analysis reveals that this is a feasible route,by synthesizing several harmonics,toward the generation of twisted attosecond pulse trains.These findings contribute to advancing the understanding of solid-state media interacting with structured light.
基金National Key Research and Development Program of China(2023YFB3811700,2022YFF0503600)Fundamental Research Funds for the Central Universities(HIT.OCEF.2022048,HIT.DZJJ.2023041)+3 种基金National Natural Science Foundation of China(52072087)Henan Provincial Science and Technology Research Project(231100230300)Natural Science Foundation of Heilongjiang Province(YQ2021E018)National Key Laboratory of Science,Technology on Advanced Composites in Special Environments,HIT。
文摘The nitrogen-vacancy(NV)color center in diamond is a promising solid-state quantum system at room temperature.However,its sensitivity is limited by its low fluorescence collection efficiency,and its coherence time is limited by spin interference of impurity electrons around the NV color center.Here,we innovatively fabricated a one-dimensional photonic crystal on the surface of diamond,which greatly improved the fluorescence intensity of the NV color centers and increased the sensitivity of NV ensembles by a factor of 2.92.In addition,the laser reflected by the photonic crystal excites impurity electrons around the NV color centers,improving the electric field environment around the NV color centers,which exponentially prolongs the dephasing time(from 209 to841 ns),opening avenues for NV color-center ensemble sensors.
基金Acknowledgements This work was supported by the National Basic Research Program of China （Grant No. 2012CB921601） and the National Natural Science Foundation of China （Grants Nos. 11125418, 91336107, 61275210, 61227902, and 61121064）.
文摘Based on single Cesium atoims trapped in a 1064 nm microscopic optical trap we have exhibited a single qubit encoded in the Cesium ＂clock states＂. The single qubit initialization, detection and the fast state rotation with high efficiencies are demonstrated and this state manipulation is crucial for quantmn information processing. The ground ~ates Rabi flopping rate of 229.0 ± 0.6 kHz is realized hy a two-photon Raman process. A clock states dephasing time of 3.0 ± 0.7 ms is measured, while all irreversible homogeneous dephasing time of 124 ± 17 ms is achieved by using the spin-echo technique. This well-controlled single atom provides an ideal quantmn qubit and quantmn node for quantum information processing.
