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quantum dynamics studies on the non-adiabatic effects of H+LiD reaction

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Frontiers of physics 2023年第3期18卷 183-191页

作者： Yuwen Bai Zijiang Yang Bayaer Buren Ye Mao Maodu Chen Key Laboratory of Materials Modification by Laser Electronand Ion Beams(Ministry of Education)School of PhysicsDalian University of TechnologyDalian 116024China

After the Big Bang,chemical reactions of hydrogen with LiH and its isotopic variants played an important role in the late stage of ***,these reactions have attracted the attention of experts in the field of molecular dynamics because of its simple *** non-adiabatic effects play a key role in many chemical reactions,while the related studies in LiH2 reactive system and its isotopic variants are not enough,so the microscopic mechanism of this system has not been fully *** this work,the microscopic mechanism of H+LiD reaction are performed by comparing both the adiabatic and non-adiabatic results to study the non-adiabatic *** reactivity of R1(H+LiD→Li+HD)channel is inhibited,while that of R2(H+LiD→D+LiH)channel is enhanced when the non-adiabatic couplings are *** R1 channel,a direct stripping process dominates this channel and the main reaction mechanism is not influenced by the non-adiabatic *** R2 channel,at relatively low collision energy,the dominance changes from a rebound process to the complex-forming mechanism when the non-adiabatic effects are considered,whereas the rebound collision approach still dominates the reaction at relatively high collision energy in both *** presented results provide a basis for further detailed study on this importantly astrophysical reaction system.

关键词： non-adiabatic effects quantum dynamics time-dependent wave packet astrophysical reaction

Dynamical learning of non-Markovian quantum dynamics

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Chinese Physics B 2022年第1期31卷 165-169页

作者：杨锦涛曹俊鹏杨文力 Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China Songshan Lake Materials Laboratory Dongguan 523808China Peng Huanwu Center for Fundamental Theory Xi'an 710127China Institute of Modern Physics Northwest UniversityXi'an 710127China School of Physical Sciences Northwest UniversityXi'an 710127China Shaanxi Key Laboratory for Theoretical Physics Frontiers Xi'an 710127China

We study the non-Markovian dynamics of an open quantum system with machine *** observable physical quantities and their evolutions are generated by using the neural *** the pre-training is completed,we fix the weights in the subsequent processes thus do not need the further gradient *** find that the dynamical properties of physical quantities obtained by the dynamical learning are better than those obtained by the learning of Hamiltonian and time evolution *** dynamical learning can be applied to other quantum many-body systems,non-equilibrium statistics and random processes.

关键词： machine learning quantum dynamics open quantum system

State-to-state integral cross sections and rate constants for the N^(+)(3P)+HD→NH^(+)/ND^(+)+D/H reaction:Accurate quantum dynamics studies

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Chinese Physics B 2022年第9期31卷 111-117页

作者：陈航航杨紫江陈茂笃 Key Laboratory of Materials Modification by Laser Electronand Ion Beams(Ministry of Education)School of PhysicsDalian University of TechnologyDalian 116024China

The reactive collisions of nitrogen ion with hydrogen and its isotopic variations have great significance in the field of ***,the state-to-state quantum time-dependent wave packet calculations of N^(+)(3P)+HD→NH^(+)/ND^(+)+D/H reaction are carried out based on the recently developed potential energy surface[***.2122203(2019)].The integral cross sections(ICSs)and rate coefficients of both channels are precisely determined at the state-to-state *** results of total ICSs and rate coefficients present a dramatic preference on the ND+product over the NH^(+)product,conforming to the long-lived complex-forming *** state-resolved ICSs indicate that both the product molecules are difficult to excite to higher vibrational states,and the ND^(+)product has a hotter rotational state ***,the integral cross sections and rate coefficients are precisely determined at the state-to-state level and insights are provided about the differences between the two *** present results would provide an important reference for the further experimental studies at the finer level for this interstellar chemical *** datasets presented in this paper,including the ICSs and rate coefficients of the two products for the title reaction,are openly available at https://***/10.57760/sciencedb.j00113.00034.

关键词： quantum dynamics integral cross sections rate coefficients

quantum dynamics of charge transfer on the one-dimensional lattice:Wave packet spreading and recurrence

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Chinese Physics B 2016年第1期25卷 817-830页

作者： V N Likhachev O I Shevaleevskii G A Vinogradov Emanuel Institute of Biochemical Physics Russian Academy of Sciences

The wave function temporal evolution on the one-dimensional （ID） lattice is considered in the tight-binding approxi- mation. The lattice consists of N equal sites and one impurity site （donor）. The donor differs from other lattice sites by the on-site electron energy E and the intersite coupling C. The moving wave packet is formed from the wave function initially localized on the donor. The exact solution for the wave packet velocity and the shape is derived at different values E and C. The velocity has the maximal possible group velocity v = 2. The wave packet width grows with time -t1/3 and its amplitude decreases ,- t-1/3. The wave packet reflects multiply from the lattice ends. Analytical expressions for the wave packet front propagation and recurrence are in good agreement with numeric simulations.

关键词： quantum dynamics tight-binding approximation charge transport

quantum dynamics of an impurity-doped Bose–Einstein condensate system

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Communications in Theoretical Physics 2020年第9期72卷 49-57页

作者： Yu Han Zhen Li Le-Man Kuang Key Laboratory of Low-Dimensional quantum Structures and quantum Control of Ministry of Education Department of Physics and Synergetic Innovation Center for Quantum Effects and ApplicationsHunan Normal UniversityChangsha 410081China

We study the quantum dynamics of an impurity-doped Bose–Einstein condensate(BEC) *** show how to generate the macroscopic quantum superposition states(MQSSs) of the BEC by the use of projective measurements on impurity atoms. It is found that the nonclassicality of MQSSs can be manipulated by changing the number of the impurities and their interaction with the BEC. It is shown that the BEC matter-wave field exhibits a collapse and revival phenomenon which reveals the quantum nature of the BEC matter-wave field. We investigate the micro-macro entanglement between the impurities and the BEC, and find enhancement of the micro-macro entanglement induced by the initial quantum coherence of the impurity atoms.

关键词： quantum dynamics an impurity-doped Bose–Einstein condensate macroscopic quantum superposition states quantum collapse and revival phenomenon micro-macro entanglement

Novel potential energy surface-based quantum dynamics of ion–molecule reaction O^++ D_2→OD^++ D

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Chinese Physics B 2018年第4期27卷 276-280页

作者：王宪龙高峰高守宝张路路宋玉志孟庆田 School of Physics and Electronics Shandong Normal University

According to a novel electronic ground-state potential energy surface of H2O^＋（X^4 A″）,we calculate the reaction probabilities and the integral cross section for the titled reaction O^＋＋ D2→OD^＋＋ D by the Chebyshev wave packet propagation *** reaction probabilities in a collision-energy range of 0.0 e V–1.0 e V show an oscillatory structure for the O^＋＋ D2 reaction due to the existence of the potential *** with the results of Martinez et al.,the present integral cross section is large,which is in line with experimental data.

关键词： quantum dynamics Chebyshev wave packet propagation O^+ + D2

A Branching Random Walk Method for Many-Body Wigner quantum dynamics

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Numerical Mathematics(Theory,Methods and Applications) 2019年第1期12卷 21-71页

作者： Sihong Shao Yunfeng Xiong LMAM and School of Mathematical Sciences Peking UniversityBeijing 100871China

A branching random walk algorithm for many-body Wigner equations and its numerical applications for quantum dynamics in phase space are proposed and ana-lyzed in this *** an auxiliary function,the truncated Wigner equation and its adjoint form are cast into integral formulations,which can be then reformulated into renewal-type equations with probabilistic *** prove that the first mo-ment of a branching random walk is the solution for the adjoint *** the help of the additional degree of freedom offered by the auxiliary function,we are able to produce a weighted-particle implementation of the branching random *** contrast to existing signed-particle implementations,this weighted-particle one shows a key ca-pacity of variance reduction by increasing the constant auxiliary function and has no time discretization *** canonical numerical experiments on the 2D Gaussian barrier scattering and a 4D Helium-like system validate our theoretical findings,and demonstrate the accuracy,the efficiency,and thus the computability of the proposed weighted-particle Wigner branching random walk algorithm.

关键词： Wigner equation branching random walk quantum dynamics variance reduction signed-particle Monte Carlo method adjoint equation renewal-type equations importance sam-pling resampling

A typical slow reaction H(~2S) + S_2(X^3-Σ_g^-) → SH(X^2Π)+S(~3P) on a new surface:quantum dynamics calculations

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Chinese Physics B 2014年第7期23卷 377-381页

作者：魏巍高守宝孙兆鹏宋玉志孟庆田 College of Physics and Electronics Shandong Normal University School of Physics Shandong University

quantum dynamics calculations for the title reaction H（2S）＋ S2（X3∑g） → SH（X2П）＋S（3P） are performed byusing a globally accurate double many-body expansion potential energy surface [J. Phys. Chem. A 115 5274 （2011）]. The Chebyshev real wave packet propagation method is employed to obtain the dynamical information, such as reaction probability, initial state-specified integral cross section, and thermal rate constant. It is found not only that there is a reaction threshold near 0.7 eV in both reaction probabilities and integral cross section curves, but also that both the probability and cross section increase firstly and then decrease as the collision energy increases. The existence of the resonance structure in both the probability and cross section curves is ascribed to the deep potential well. The calculation of the rate constant reveals that the reaction occurring on the potential energy surface of the ground-state HS2 is slow to take place.

关键词： quantum dynamics Chebyshev real wave packet propagation H + S2

Numerical Path Integral Approach to quantum dynamics and Stationary quantum States

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Communications in Computational Physics 2015年第6期18卷 91-103页

作者： Ilkka Ruokosenmaki Tapio T.Rantala Department of Physics Tampere University of TechnologyFinland

Applicability of Feynman path integral approach to numerical simulations of quantum dynamics of an electron in real time domain is *** quantum dynamics is demonstrated with one dimensional test cases(quantum dot models)and performance of the Trotter kernel as compared with the exact kernels is ***,a novel approach for finding the ground state and other stationary sates is *** is based on the incoherent propagation in real *** both approaches the Monte Carlo grid and sampling are tested and compared with regular grids and *** asses the numerical prerequisites for all of the above.

关键词： Path integral real time domain quantum dynamics incoherent propagation stationary states