Precise experimental control and characterization of electron wave packet dynamics driven by external optical fields remain a fundamental challenge,particularly at ultrafast temporal and sub-microscopic spatial scales...Precise experimental control and characterization of electron wave packet dynamics driven by external optical fields remain a fundamental challenge,particularly at ultrafast temporal and sub-microscopic spatial scales.To overcome these challenges,we introduce a photon-based simulation platform employing a traveling-wave electrooptic phase-modulated waveguide.In our setup,the incident electromagnetic pulse serves as an analog to the electron wave packet,while the traveling-wave modulation simulates the external optical driving field.Our experimental study systematically explores pulse evolution under three distinct regimes defined by the relation between the pulse duration(Δt)and the modulation period(T).When the pulse duration is significantly shorter than the modulation period,we observe a uniform spectral shift analogous to electron acceleration in dielectric laser accelerators,where spectral phase gradients represent electron momentum accumulation.Conversely,when the pulse duration greatly exceeds the modulation period,discrete diffraction patterns emerge,closely resembling the discrete sideband features of electron-photon coupling observed in photon-induced near-field electron microscopy.Notably,in the intermediate regime(T/4<Δt<T/2),the pulse spectrum exhibits Airy-function-type characteristics with self-healing effects.These experimental results provide critical insights into electron-wave interactions under external optical fields and establish a robust,programmable framework for further investigation.展开更多
We present a graphics processing units(GPU)parallelization based three-dimensional time-dependent Schrödinger equation(3D-TDSE)code to simulate the interaction between single-active-electron atom/molecule and arb...We present a graphics processing units(GPU)parallelization based three-dimensional time-dependent Schrödinger equation(3D-TDSE)code to simulate the interaction between single-active-electron atom/molecule and arbitrary types of laser pulses with either velocity gauge or length gauge in Cartesian coordinates.Split-operator method combined with fast Fourier transforms(FFT)is used to perform the time evolution.Sample applications in different scenarios,such as stationary state energies,photon ionization spectra,attosecond clocks,and high-order harmonic generation(HHG),are given for the hydrogen atom.Repeatable results can be obtained with the benchmark program PCTDSE,which is a 3DTDSE Fortran solver parallelized using message passing interface(MPI)library.With the help of GPU acceleration and vectorization strategy,our code running on a single NVIDIA 3090 RTX GPU can achieve about 10 times faster computation speed than PCTDSE running on a 144 Intel Xeon CPU cores server with the same accuracy.In addition,3D-GTDSE can also be modified slightly to simulate non-adiabatic dynamics involving the coupling of nuclear and electronic wave packets,as well as pure nuclear wave packet dynamics in the presence of strong laser fields within 3 dimensions.Additionally,we have also discussed the limitations and shortcomings of our code in utilizing GPU memory.The 3D-GTDSE code provides an alternative tool for studying the ultrafast nonlinear dynamics under strong laser fields.展开更多
The vibrational state-selected population transfer from a highly vibrationally excited level to the ground level is of great importance in the preparation of ultra-cold molecules. By using the time-dependent quantum-w...The vibrational state-selected population transfer from a highly vibrationally excited level to the ground level is of great importance in the preparation of ultra-cold molecules. By using the time-dependent quantum-wave-packet method, the population transfer dynamics is investigated theoretically for the HF molecule. A double-E-type laser scheme is proposed to transfer the population from the ｜v=16〉 level to the ground vibrational level ｜v=0〉 on the ground electronic state. The scheme consists of two steps： The first step is to transfer the population from ｜v=16〉 to ｜v=7〉 via an intermediate level ｜v=11〉, and the second one is to transfer the population from ｜v=7〉 to ｜v=0〉 via ｜v=3〉. In each step, three vibrational levels form a E-type population transfer path under the action of two temporally overlapped laser pulses. The maximal population-transfer efficiency is obtained by optimizing the laser inten- sities, frequencies, and relative delays. Cases for the pulses in intuitive and counterintuitive sequences are both calculated and compared. It is found that for both cases the population can be efficiently （over 90%） transferred from the ｜v=-16〉 level to the ｜v=0〉 level.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.12174260)the Shanghai Rising-Star Program(Grant No.21QA1406400)+1 种基金the Shanghai Science and Technology Development Fund(Grant Nos.21ZR1443500 and 21ZR1443600)supported by Research Grants Council,University Grants Committee(Grant Nos.STG3/E-704/23-N,CityU 11212721,and CityU 11204523).
文摘Precise experimental control and characterization of electron wave packet dynamics driven by external optical fields remain a fundamental challenge,particularly at ultrafast temporal and sub-microscopic spatial scales.To overcome these challenges,we introduce a photon-based simulation platform employing a traveling-wave electrooptic phase-modulated waveguide.In our setup,the incident electromagnetic pulse serves as an analog to the electron wave packet,while the traveling-wave modulation simulates the external optical driving field.Our experimental study systematically explores pulse evolution under three distinct regimes defined by the relation between the pulse duration(Δt)and the modulation period(T).When the pulse duration is significantly shorter than the modulation period,we observe a uniform spectral shift analogous to electron acceleration in dielectric laser accelerators,where spectral phase gradients represent electron momentum accumulation.Conversely,when the pulse duration greatly exceeds the modulation period,discrete diffraction patterns emerge,closely resembling the discrete sideband features of electron-photon coupling observed in photon-induced near-field electron microscopy.Notably,in the intermediate regime(T/4<Δt<T/2),the pulse spectrum exhibits Airy-function-type characteristics with self-healing effects.These experimental results provide critical insights into electron-wave interactions under external optical fields and establish a robust,programmable framework for further investigation.
基金supported by the GHfund A(Grant No.ghfund202407013663)the Fundamental Research Funds for the Central Universities(Grant No.GK202207012)+4 种基金Shaanxi Province(Grant No.QCYRCXM-2022-241)the National Key Research and Development Program of China(Grant No.2022YFE0134200)Guangdong Basic and Applied Basic Research Foundation(Grant No.2025A1515011117)the Natural Science Foundation of Jilin Province(Grant No.20220101016JC)the National Natural Science Foundation of China(Grant Nos.12374238,11934004,and 11974230)。
文摘We present a graphics processing units(GPU)parallelization based three-dimensional time-dependent Schrödinger equation(3D-TDSE)code to simulate the interaction between single-active-electron atom/molecule and arbitrary types of laser pulses with either velocity gauge or length gauge in Cartesian coordinates.Split-operator method combined with fast Fourier transforms(FFT)is used to perform the time evolution.Sample applications in different scenarios,such as stationary state energies,photon ionization spectra,attosecond clocks,and high-order harmonic generation(HHG),are given for the hydrogen atom.Repeatable results can be obtained with the benchmark program PCTDSE,which is a 3DTDSE Fortran solver parallelized using message passing interface(MPI)library.With the help of GPU acceleration and vectorization strategy,our code running on a single NVIDIA 3090 RTX GPU can achieve about 10 times faster computation speed than PCTDSE running on a 144 Intel Xeon CPU cores server with the same accuracy.In addition,3D-GTDSE can also be modified slightly to simulate non-adiabatic dynamics involving the coupling of nuclear and electronic wave packets,as well as pure nuclear wave packet dynamics in the presence of strong laser fields within 3 dimensions.Additionally,we have also discussed the limitations and shortcomings of our code in utilizing GPU memory.The 3D-GTDSE code provides an alternative tool for studying the ultrafast nonlinear dynamics under strong laser fields.
基金Li-hang Li thanks Dr. Yin Huang for assistance. The project is supported by the Specialized Research Fund for the Doctoral Program of Higher Education （No.20130041120053）, SRF for ROCS, SEM, the Sci- ence and Technology Research Funds of the Depart- ment of Education of Liaoning Province （L2013014）, the National Magnetic Confinement Fusion Science Pro- gram （No.2013GB109005）, the Fundamental Research Funds for the Central Universities （DUT12RC（3）60）, and the NationM Natural Science Foundation of China （No.21473018, No.10974024, and No.11274056）.
文摘The vibrational state-selected population transfer from a highly vibrationally excited level to the ground level is of great importance in the preparation of ultra-cold molecules. By using the time-dependent quantum-wave-packet method, the population transfer dynamics is investigated theoretically for the HF molecule. A double-E-type laser scheme is proposed to transfer the population from the ｜v=16〉 level to the ground vibrational level ｜v=0〉 on the ground electronic state. The scheme consists of two steps： The first step is to transfer the population from ｜v=16〉 to ｜v=7〉 via an intermediate level ｜v=11〉, and the second one is to transfer the population from ｜v=7〉 to ｜v=0〉 via ｜v=3〉. In each step, three vibrational levels form a E-type population transfer path under the action of two temporally overlapped laser pulses. The maximal population-transfer efficiency is obtained by optimizing the laser inten- sities, frequencies, and relative delays. Cases for the pulses in intuitive and counterintuitive sequences are both calculated and compared. It is found that for both cases the population can be efficiently （over 90%） transferred from the ｜v=-16〉 level to the ｜v=0〉 level.
