检索结果-南通市图书馆

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 sample temperature on femtosecond laser ablation of copper

在线全文

学校读者我要写书评

暂无评论

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 temperature.For 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 model.The simulation results show that both electron peak temperature and the relaxation time needed to reach equilibrium increase as initial sample temperature rises.When 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 values.This 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

Core level excitation spectra of La and Mn ions in LaMnO3

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2024年第3期33卷 327-332页

作者：李福建程新路张红 Institute of atomic and molecular Physics Sichuan UniversityChengdu 610065Chin

Manganese-based perovskite is popular for research on ferromagnetic materials,and its spectroscopic studies are essential for understanding its electronic structure,dielectric,electrical,and magnetic properties.In this paper,the M-edge spectra of La ions and the M-edge,L-edge,and K-edge spectra of Mn ions in LaMnO3 are calculated by considering both the free-ion multiplet calculation and the crystal field effects.We analyze spectral shapes,identify peak origins,and estimate the oxidation states of La and Mn ions in LaMnO3 theoretically.It is concluded that La ions in LaMnO3 predominantly exist in the trivalent state,while Mn ions exist primarily in the trivalent state with a minor presence of tetravalent ions.Furthermore,the calculated spectra are in better conformity with the experimental spectra when the proportion of Mn3+is 90%and Mn4+is 10%.This article enhances our comprehension of the oxidation states of La and Mn within the crystal and also provides a valuable guidance for spectroscopic investigations of other manganates.

关键词： lanthanum manganate the core level excitation spectra free-ion multiplet calculation oxidation state

Experimental realization of quantum cryptography communication in free space

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2005年第2期48卷 237-246页

作者： WANG Chuan1, ZHANG Jingfu1, WANG Pingxiao1, DENG Fuguo1, AI Qing1 & LONG Guilu1,2 1. Department of Physics, Key Laboratory for Quantum Information and Measurements, Tsinghua Univer- sity, Beijing 100084, China 2. Center for atomic and molecular nanosciences, Tsinghua University, Beijing 100084, China Department of Physics Key Laboratory for Quantum Information and Measurements Tsinghua University Beijing China atomic and molecular nanosciences Tsinghua University Beijing China

Utilizing linear optical devices, the principle of B92 quantum key distribution (QKD) protocol is demonstrated in free space with a distance of transmission of 2.2 meters. The faint laser pulses with 650 nm wavelength are used as the single photon sources. The experimental results show that the eavesdropping behavior in the signal transmission can be detected. We also discuss the problems and solutions in using the quantum cryptography communication practically. It is pointed out that one of the approaches to increasing the distance of the quantum communication is to overcome the attenuation of the single photon in transmission. This could not be solved by the use of single photon source, and new quantum communication protocols are needed to solve these problems.

关键词： quantum key distribution, free space, linear optics, faint pulses.

Theoretical investigation of excited dipole bound states of alkali-containing diatomic anions

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2024年第5期33卷 389-393页

作者：连艺肖利丹边丽丽徐海峰闫冰 Institute of atomic and molecular Physics Jilin UniversityChangchun 130012China

Information about electronic excited states of molecular anions plays an important role in investigating electron attachment and detachment processes.Here we present a high-level theoretical study of the electronic structures of 12 alkali-metal-containing diatomic anions MX-(MX = LiH,LiF,LiCl,NaF,NaCl,NaBr,RbCl,KCl,KBr,RbI,KI and CsI).The equation-of-motion electron-attachment coupled-cluster singles and doubles(EOM-EA-CCSD) method is used to calculate the electron binding energies(EBEs) of 10 electronic excited states of each of the 12 molecule anions.With addition of different s-/p-/d-type diffusion functions in the basis set,we have identified possible excited dipole bound states(DBSs) of each anion.With the investigation of EBEs on the 12 MXs with dipole moment(DM) up to 12.1 D,we evaluate the dependence of the number of anionic excited DBSs on molecular DM.The results indicate that there are at least two or three DBSs of anions with a molecular DM larger than 7 D and a molecule with DM > 10 D can sustain a π-DBS of the anion.Our study has some implications for the excited DBS electronic states of alkali-metal-containing diatomic molecules.

关键词： anions dipole bound states alkali-metal-containing diatomic molecules

Excitation and ionization of OCS molecules in strong UV and NIR laser fields

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2024年第7期33卷 285-291页

作者：师慧军刘洋孙添吕航徐海峰 Institute of atomic and molecular Physics Jilin UniversityChangchun 130012China

Rydberg state excitation(RSE) is a highly non-linear physical phenomenon that is induced by the ionization of atoms or molecules in strong femtosecond laser fields. Here we observe that both parent and fragments(S, C, OC) of the triatomic molecule carbonyl sulfide(OCS) can survive strong 800 nm or 400 nm laser fields in high Rydberg states. The dependence of parent and fragment RSE yields on laser intensity and ellipticity is investigated in both laser fields, and the results are compared with those for strong-field ionization. Distinctly different tendencies for laser intensity and ellipticity are observed for fragment RSE compared with the corresponding ions. The mechanisms of RSE and strong-field ionization of OCS molecules in different laser fields are discussed based on the experimental results. Our study sheds some light on the strong-field excitation and ionization of molecules irradiated by femtosecond NIR and UV laser fields.

关键词： Rydberg state excitation strong field carbonyl sulfide ionization

Eavesdropping in a quantum secret sharing protocol based on Grover algorithm and its solution

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2010年第3期53卷 491-495页

作者： HAO Liang1, LI JunLin1 & LONG GuiLu1,2 1Key Laboratory for atomic and molecular nanosciences and Department of Physics, Tsinghua University, Beijing 100084, China 2Tsinghua National Laboratory for Information Science and Technology, Beijing 100084, China Key Laboratory for atomic and molecular nanosciences and Department of Physics Tsinghua University Beijing China Tsinghua National Laboratory for Information Science and Technology Beijing China

A detailed analysis has showed that the quantum secret sharing protocol based on the Grover algorithm (Phys Rev A, 2003, 68: 022306) is insecure. A dishonest receiver may obtain the full information without being detected. A quantum secret-sharing protocol is presents here, which mends the security loophole of the original secret-sharing protocol, and doubles the information capacity.

关键词： quantum secret sharing Grover algorithm quantum cryptography quantum search algorithm

Measuring-basis-encrypted six-state quantum key distribution scheme

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2006年第1期16卷 84-89页

作者： CHEN Pan1, DENG Fuguo1, WANG Pingxiao1 and LONG Guilu1,2 (Key Laboratory for Quantum Information and Measurements and Department of Physics, Tsinghua University, Beijing 100084, China 2. Key Laboratory for atomic and molecular nanosciences, Tsinghua University, Beijing 100084, China) Key Laboratory for Quantum Information and Measurements Department of Physics Tsinghua University Beijing 100084 China Key Laboratory for atomic and molecular nanosciences Tsinghua University Beijing 100084 China

A six-state quantum key distribution scheme with measuring-basis encryption technique, which is based on the six-state protocol and the MBE protocol, is proposed. In this modified six-state quantum key distribution protocol, Alice and Bob use a control key to synchronize the use of their measuring-basis so that they always use the same measuring-basis. This modified six-state quantum key distribution protocol retains the advantage of higher security and at the same time has a higher efficiency.

关键词： quantum key distribution measuring-basis encrypted six-state security.

A scheme to implement the Deutsch-Josza algorithm on a superconducting charge-qubit quantum computer

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2006年第6期16卷 594-599页

作者： HUO Wenyi and LONG Guilu (Key Laboratory for Quantum Information and Measurements, and Department of Physics, Tsinghua University, Beijing 100084, China Key Laboratory for atomic and molecular nanosciences, Tsinghua University, Beijing 100084, China) Key Laboratory for Quantum Information and Measurements Department of Physics Tsinghua University Bejjing 100084 China Key Laboratory for atomic and molecular nanosciences Tsinghua University Bejing 100084 China

We have studied the implementation of the Deutsch-Josza quantum algorithm in a superconducting charge-qubit quantum computer. Different from previous studies, we have used the inductance coupled system of You et al. The detailed pulse sequences have been designed for the four possible functions in a 2-qubit system. The result is generalized to an arbitrary n-qubit system. This scheme will be useful for practical implementation of the algorithm.

关键词： superconducting quantum computer Deutsch-Josza algorithm.

Suppression of Phase and Amplitude Damping Decoherence in a Three-Level Atom in A-Configuration Using Bang-Bang Controls

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2007年第7期48卷 71-74页

作者： WANG Yan-Hui LIU Xiao-Shu LONG Gui-Lu1 Key Laboratory for atomic and molecular nanosciences and Department of Physics,Tsinghua University,Beijing 100084,China2 Tsinghua National Laboratory for Information Science and Technology,Tsinghua University,Beijing 100084,China Key Laboratory for atomic and molecular nanosciences and Department of Physics Tsinghua University Beijing 100084 China Tsinghua National Laboratory for Information Science and Technology Tsinghua University Beijing 100084 China

In this paper,we present decoupling bang-bang operations for the suppression of general decoherence,bothamplitude and phase damping,in a three-level system in A-configuration.We give a program to design a sequence ofp... 详细信息

关键词： bang-bang operation general decoherence three-level system