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Effects of 5f-elements on electronic structures and spectroscopic properties of gold superatom model

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Chinese Physics B 2016年第8期25卷 1-9页

作者：高阳王志刚 Institute of atomic and molecular Physics Jilin University Changchun 130012 China Jilin Provincial key laboratory of Applied atomic and molecular Spectroscopy (Jilin University) Changchun 130012 China

5f-elements encaged in a gold superatomic cluster are capable of giving rise to unique optical properties due to their hyperactive valence electrons and great radial components of 5f/6d orbitals. Herein, we review our first-principles studies on electronic structures and spectroscopic properties of a series of actinide-embedded gold superatomic clusters with different dimensions. The three-dimensional（3D） and two-dimensional（2D） superatom clusters possess the 18-electron configuration of 1S21P61D10 and 10-electron configuration of 1S21P41D4, respectively. Importantly, their electronic absorption spectra can also be effectively explained by the superatom orbitals. Specifically, the charge transfer（CT） transitions involved in surface-enhance Raman spectroscopy（SERS） spectra for 3D and 2D structures are both from the filled 1D orbitals, providing the enhancement factors of the order of ～ 10^4 at 488 nm and ～ 10^5 at 456 nm, respectively. This work implies that the superatomic orbital transitions involved in 5f-elements can not only lead to a remarkable spectroscopic performance, but also a new direction for optical design in the future.

关键词： 5f-electrons ds-electrons superatom first-principles

Interference effect of photoionization of hydrogen atoms by ultra-short and ultra-fast high-frequency chirped pulses

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Chinese Physics B 2019年第8期28卷 112-118页

作者： Ningyue Wang Aihua Liu Institute of atomic and molecular Physics Jilin UniversityChangchun 30012China Jilin Provincial key laboratory of Applied atomic and molecular Spectroscopy Jilin UniversityChangchun 130012China

The photoionization of a hydrogen atom from its ground state with ultra-fast chirped pulses is investigated by numerically solving the time-dependent Schrodinger equation within length,velocity,and Kramers-Henneberger *** results for all gauges for chirp-free pulses agree with the prediction of dynamic interference for ground state hydrogen atoms predicted recently by Jiang and Burgdorfer[*** 26,19921(2018)].In addition,we investigated photoelectron spectra of hydrogen atoms by chirped laser pulses,and showed that dynamic interference effect will be weaken for pulses with increasing linear *** numerical results can be understood and discussed in terms of an interplay of photoelectron wavepackets from first and second halves of laser enevelop,including the ac Stark energy level shift of the photoelectron final state and atomic stabilization effect at ultra-high intensities.

关键词： dynamic interference super-intense laser chirped pulses

Amplitude and rotation of the ellipticity of harmonics from a linearly polarized laser field

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Chinese Physics B 2022年第10期31卷 88-95页

作者： Ping Li Na Gao Rui-Xian Yu Jun Wang Su-Yu Li Fu-Ming Guo Yu-Jun Yang Institute of atomic and molecular Physics Jilin UniversityChangchun 130012China Jilin Provincial key laboratory of Applied atomic and molecular Spectroscopy(Jilin University) Changchun 130012China

We simulate the dynamic response of H^(+)_(2) in a linearly polarized laser field by numerically solving the time-dependent Schr?dinger *** elliptically polarized high-order harmonics generated by H^(+)_(2)irradiated by the linearly polarized laser field are systematically *** result shows that the amplitude and rotation of the ellipticity of harmonics are affected by the alignment angle and internuclear distance of the *** the change in forces acted on the ionized electrons and the trajectories of the electrons,the phenomena are found to be due to the change in the direction of the total Coulomb forces from the two nuclei felt by the recollided ionized electrons in the direction perpendicular to the laser polarization *** on the influence law,we can select the harmonics with a specific frequency band under different alignment angles and then synthesize the isolated attosecond pulses with different rotations,which can be continuously converted from right-handed circular polarization,linear polarization,and left-handed circular polarization by changing the alignment *** study provides a new possible approach to the real-time detection of molecular states by using attosecond pulses and obtaining more optimized harmonics with molecular properties.

关键词： high-order harmonic ellipticity rotation attosecond pulses

Direct Observation on H-Elimination Enhancement from C_(2)H_(4) through Non-Adiabatic Process by Femtosecond Laser Induced Coulomb Explosion

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Chinese Physics Letters 2024年第5期41卷 17-22页

作者：金无维王春成赵晓戈杨译章任殿相刘泽槿李孝开罗嗣佐丁大军 Institute of atomic and molecular Physics Jilin UniversityChangchun 130012China Jilin Provincial key laboratory of Applied atomic and molecular Spectroscopy Jilin UniversityChangchun 130012China

Ethylene, the simplest model of a carbon-carbon double bond system, is pivotal in numerous chemical and biological processes. By employing intense infrared laser pump-probe techniques alongside coincidence measurements, we investigate the ultrafast non-adiabatic dynamics involved in the breakage of carbon-carbon double bonds and hydrogen elimination in dissociation of ethylene. Our study entails analyzing the dynamic kinetic energy release spectra to assess three bond-breaking scenarios, movements of nuclei, and structural changes around the carbon atoms. This allows us to evaluate the relaxation dynamics and characteristics of various dissociative states. Notably, we observe a significant rise in the yield of fragments resulting from C–H bond breakage with the delay time extended, suggesting non-adiabatic coupling through conical intersections from C–C bond breakage as a probable cause.

关键词： pump Femto adiabatic

Effect of laser intensity on quantum trajectories in the macroscopic high-order harmonic generation

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Chinese Physics B 2019年第11期28卷 52-59页

作者： Yun Pan Fuming Guo Yujun Yang Dajun Ding Institute of atomic and molecular Physics Jilin UniversityChangchun 130012China Jilin Provincial key laboratory of Applied atomic and molecular Spectroscopy(Jilin University) Changchun 130012China

We macroscopically investigate the effect of the laser intensity and gas density on quantum trajectories in the highorder harmonic generation of Ne atoms irradiated by few-cycle, 800-nm laser pulses. The time–frequency profile of the harmonics shows that the long quantum trajectory is dominant at both lower and higher gas densities for a low laser intensity. At high laser intensities, the long quantum trajectory plays an important role for lower gas densities, while the short quantum trajectory is dominant at higher gas densities. An analysis of the phase mismatch for high-order harmonic generation shows that the primary emission of the quantum trajectories is determined by dynamic changes in the laser electric field during the propagation process.

关键词： high-order harmonic generation quantum trajectory

Numerical simulation of end-pumped CW Nd^(3+):GdVO_4 laser at 1063nm

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Chinese Physics B 2008年第5期17卷 1809-1816页

作者：祖宁宁孙桂娟戴振文 Department of Physics Jilin University key laboratory of Coherent Light Atomic and Molecular Spectroscopy Ministry of Education

A theoretical model to simulate an end-pumped CW Nd^3＋：GdVO4 laser at 1063 nm is presented. Its essence is to use the propagation equations to demonstrate the spatial evolutions of the pump and the laser powers in the cavity, hence it is applicable to both low and high gain lasers. The simulation results obtained by this model are in good agreement with the experimental observations reported in the literature for a Ti：sapphlre-pumped Nd^3＋：GdVO4 laser. Moreover, some parameters, such as the reflectivity of output coupler, the spot size of laser beam and the crystal length, are discussed with a view to optimizing the laser performance.

关键词： end-pumped Nd^3+:GdVO4 1063nm laser

Bang-bang control suppression of amplitude damping in a three-level atom

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Science China(Physics,Mechanics & Astronomy) 2008年第1期51卷 29-37页

作者： CAO WanCang LIU XiaoShu BAI HongBo LONG GuiLu Department of Physics Chifeng CollegeChifeng 024001China key laboratory for atomic and molecular nanosciences and Department of Physics Tsinghua UniversityBeijing 100084China Tsinghua National laboratory for Information Science and Technology Beijing 100084China

By using quantum bang-bang control technique,we studied the suppression of amplitude damping,or energy dissipation,in a three-level atom in various *** have explicitly given the bang-bang control groups in three diffe... 详细信息

关键词： dynamical control decoherence bang-bang control group amplitude damping

Controllable double electromagnetically induced transparency in a closed four-level-loop cavity-atom system

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Chinese Physics B 2017年第7期26卷 117-122页

作者：郭苗迪苏雪梅 key laboratory of Coherent Light Atomic and Molecular Spectroscopy (Ministry of Education) and College of Physics Jilin University

We present a theoretical study of an optical cavity coupled with single four-level atoms in closed loop formed via applied control lasers. The transmitted probe field from the cavity is analyzed. We show that the electromagnetically induced transparency（EIT） in the cavity and the normal mode splitting will be very different with changing the closed interaction phase and the intensity of the free-space control laser. This coupled cavity-atom system presents a variational double-EIT that comes from modulating the splitting of the dark state, which means that we could realize the gradual transfer between one EIT peak and two EIT peaks by adjusting the applied control lasers, and the normal mode splitting sidebands will shift slightly by changing the free-space control laser. This means that we could control the output cavity probe field more freely and it is easer to realize optical switch controlled by more parameters. We also depict the angular dispersion of the intracavity probe field in different free-space control laser. The large phase shift（-π → π） of the reflected intracavity probe field will be very useful for optical temporal differentiation and quantum phase gate.

关键词： cavity quantum electrodynamics double electromagnetically induced transparency all optical switch cross phase modulation

Effect of sample temperature on femtosecond laser ablation of copper

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Chinese Physics B 2024年第2期33卷 377-385页

作者：党伟杰陈雨桐陈安民金明星 Institute of atomic and molecular Physics Jilin UniversityChangchun 130012China Jilin Provincial key laboratory of Applied atomic and molecular Spectroscopy Jilin UniversityChangchun 130012China

We conduct an experimental study supported by theoretical analysis of single laser ablating copper to investigate the interactions between laser and material at different sample temperatures,and predict the changes of ablation morphology and lattice *** investigating the effect of sample temperature on femtosecond laser processing,we conduct experiments on and simulate the thermal behavior of femtosecond laser irradiating copper by using a two-temperature *** simulation results show that both electron peak temperature and the relaxation time needed to reach equilibrium increase as initial sample temperature *** the sample temperature rises from 300 K to 600 K,the maximum lattice temperature of the copper surface increases by about 6500 K under femtosecond laser irradiation,and the ablation depth increases by 20%.The simulated ablation depths follow the same general trend as the experimental *** work provides some theoretical basis and technical support for developing femtosecond laser processing in the field of metal materials.

关键词： femtosecond laser two-temperature model sample temperature ablation depth