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Chinese Physics B 2009年第3期18卷 888-893页

作者：陈丽邵晓强张寿 Department of Physics College of ScienceYanbian University Center for the Condensed-Matter Science and Technology Harbin Institute of Technology

The influences of dipole-dipole interaction and detuning on the entanglement between two atoms with different initial tripartite entangled W-like states in the Tavis Cummings model have been investigated by means of Wootters＇ concurrence, respectively. The results show that the entanglement between the two atoms can be enhanced via appropriately tuning the strength of dipole-dipole interaction of two atoms or the detunings between atom and cavity, and the so-called sudden death effect can he weakened simultaneously.

关键词： concurrence sudden death of entanglement dipole-dipole interaction detuning

Sudden death of entanglement of two atoms interacting with thermal fields

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Chinese Physics B 2011年第8期20卷 30-38页

作者：罗成立缪龙郑小兰陈子翃廖长庚 Department of Physics Fuzhou University

We investigate the entanglement dynamics of two initially entangled atoms each interacting with a thermal field. We show that the two entangled atoms become completely disentangled in a finite time and that the lost information cannot return to the atomic system when the mean photon number of the thermal field exceeds a critical value （3.3584）, even though the whole system is lossless. Then we study how the detuning between the atomic transition frequency and the field frequency and the disparity between two coupling rates would affect the evolution of the entanglement of the atomic system.

关键词： entanglement sudden death thermal field asymmetric detuning

Enhanced optical molasses cooling for Cs atoms with largely detuned cooling lasers

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Chinese Physics B 2020年第2期29卷 249-253页

作者： Di Zhang Yu-Qing Li Yun-Fei Wang Yong-Ming Fu Peng Li Wen-Liang Liu Ji-Zhou Wu Jie Ma Lian-Tuan Xiao Suo-Tang Jia State Key Laboratory of Quantum Optics and Quantum Optics Devices Institute of Laser SpectroscopyCollege of Physics and Electronics EngineeringShanxi UniversityTaiyuan 030006China Collaborative Innovation Center of Extreme Optics Shanxi UniversityTaiyuan 030006China

We report a detailed study of the enhanced optical molasses cooling of Cs atoms,whose large hyperfine structure allows to use the largely red-detuned cooling *** find that the combination of a large frequency detuning of about-110 MHz for the cooling laser and a suitable control for the powers of the cooling and repumping lasers allows to reach a cold temperature of^5.5μ*** obtain 5.1×10^7 atoms with the number density around 1×10^12 cm^-*** result gains a lower temperature than that got in other experiments,in which the cold Cs atoms with the temperature of^10μK have been achieved by the optical molasses cooling.

关键词： optical molasses frequency detuning magneto-optical trap laser cooling

Optical bistability and multistability in a three-level △-type atomic system under the nonresonant condition

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Chinese Physics B 2009年第3期18卷 1072-1076页

作者：陈爱喜王志平陈德海徐彦秋 Department of Applied Physics East China Jiaotong University

Under a nonresonant condition, we theoretically investigate hybrid absorptive-dispersive optical bistability and multistability behaviours in a three-level △-type system by using a microwave field to drive a hyperfine transition between two upper excited states inside a unidirectional ring cavity. We find that the optical bistability and multistability behaviours can be controlled by adjusting the intensity of the microwave field or the intensity of the coherent coupling field. Furthermore, our studies show an interesting phenomenon of the transition from the optical bistability to the optical multistability only by changing the negative detuning of the coupling field into the positive detuning of the coupling field.

关键词： optical bistability multistability detuning

Quantum dynamic behaviour in a coupled cavities system

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Chinese Physics B 2012年第6期21卷 26-32页

作者：彭俊邬云文李小娟 College of Physics Mechanical and Electrical EngineeringJishou University

The dynamic behaviour of the two-site coupled cavities model which is doped with ta wo-level system is investi-gated. The exact dynamic solutions in the general condition are obtained via Laplace transform. The simple analytical solutions are obtained in several particular cases, which demonstrate the clear and simple physical picture for the quan-tum state transition of the system. In the large detuning or hoppling case, the quantum states transferring between qubits follow a slow periodic oscillation induced by the very weak excitation of the cavity mode. In the large coupling case, the system can be interpreted as two Jaynes-Cummings model subsystems which interact through photon hop between the two cavities. In the case of λ≈△〉〉 g, the quantum states transition of qubits is accompanied by the excitation of the cavity, and the cavity modes have the same dynamic behaviours and the amplitude of probability is equM to 0.25 which does not change with the variation of parameter.

关键词： coupled cavities quantum dynamics behaviour detuning two-level system

Entanglement Dynamics of Two Atoms in a Double Damping Jaynes-Cummings System

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Communications in Theoretical Physics 2018年第10期70卷 477-484页

作者： Zhi-Jian Li Jing Zhang Feng-Xian Huang Li-Li Cao Zhong-Wen Han North University of China Shuozhou 036000 China College of Physics and Electronic Engineering Shanxi University Taiyuan 030006 China

The entanglement between two stationary qubits is a kind of valuable quantum resources in quantum information or quantum network. This paper investigates the time evolution of the entanglement between two atoms,which are initially prepared in the Bell states and each of which interacts with its own cavity field in the identical and non-identical double damping Jaynes-Cummings(J-C) system. It mainly considers the effect of the atomic spontaneous decay Γ and the decay of cavity field κ on the two-qubit entanglement in such system. While causing the decay of entanglement, Γ and κ can also play a positive role in the entanglement evolution, which may imply a way to better control and maintain the entanglement. What is more, the rules governing the transfer of entanglement between two-qubit subsystems in strong coupling regime are finally studied by taking Γ and κ into consideration.

关键词： entanglement concurrence detuning decay

Quantum Discord Dynamics of Three Qubits in Non-Markovian Environments

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Communications in Theoretical Physics 2014年第6期61卷 691-698页

作者：张燕刘金明李艳杰 State Key Laboratory of Precision Spectroscopy East China Normal University

We investigate the dynamics of palrwise quantum discord （QD） for a mixed three-qubit W-type state in three independent non-Markovian reservoirs at zero temperature, each of which is modeled by a leaky cavity with Lorentzian spectral density. The influence of the environment＇s amount of non-Markovianity, the detuning between the qubit frequency and the cavity centre frequency, and the purity of the initial state on the QD dynamics are analyzed in detail. It is found that in the non-Maxkovian regime the system-reservoir interactions induce QD revivals and oscillations no matter whether the detuning is zero or not. Moreover, QD can be preserved for a long time if the non-Markovian condition and the detuning condition are satisfied simultaneously.

关键词： quantum discord non-Markovian environment W-type state detuning

Localization of elastic waves in one-dimensional detuned phononic crystals with flexoelectric effect

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International Journal of Smart and Nano Materials 2022年第2期13卷 244-262页

作者： Cheng Shen Yifan Kong Tian Jian Lu Shasha Yang State Key Laboratory of Mechanics and Control of Mechanical Structures Nanjing University of Aeronautics and AstronauticsNanjingPRChina MIIT Key Laboratory of Multifunctional Lightweight Materials and Structures Nanjing University of Aeronautics and AstronauticsNanjingPRChina Space Structure and Mechanism Technology Laboratory of China Aerospace Science and Technology Group Co.Ltd ShanghaiP.R China School of Mechanical Engineering Nanjing Vocational University of Industry TechnologyNanjingP.R China

Although forbidden band effect in perfectly periodic phononic crystals(PC)is very attractive,random disordered(***)phenomenon is inevitable in engineering processing,thus explor-ing the effect of detuning on the wave characteristics of PC becomes a *** this study,fundamental governing equa-tions and boundary conditions are derived from the principle of virtual *** characteristics and localization factor of one-dimensional(1D)detuned nano-PC are investigated based on the transfer matrix method,with flexoelectric effect duly accounted ***,with BaTiO_(3)􀀀SrTiO_(3) nano-PC taken for illustration,forbidden band properties and localization factor of 1D elastic waves in harmonic and detuned states are systematically *** is demonstrated that localization factor can characterize the energy band structure of 1D PC *** effect tends to widen the width of forbidden band with increasing detuning,and detuning is linearly related to the *** forbidden band is more sensitive to flexoelectric coefficient detuning than thickness *** research results provide useful theoretical guidance for designing high-frequency nanoscaled devices with the function of filtering based on band gap effect of nano-PC.

关键词： Flexoelectric effect phononic crystal detuning localization factor forbidden band

Spectrum of the Micromaser with Kerr Medium

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Communications in Theoretical Physics 2002年第11期37卷 637-640页

作者： WUShu－Dong DepartmentofPhysics HuazhongUniversityofScienceandTechnologyWuhan430074China

We have established the master equation for the micromaser with Kerr medium field density operator, studied the spectrum of the micromaser with Kerr medium and analyzed the influence of Kerr effect and the detuning on the spectrum. In the thermal-atom regime, we find that Kerr effect broadens linewidth D and increases frequency-shift S, and that the detuning Δ narrows linewidth D and increases frequency-shift S as a whole. Moreover Kerr effect leads to oscillatings more rapidly in the resonance peaks, which means that it causes quantum noise. As a whole, with the increase of cavity-length L, the linewidth D and frequency-shift S gradually increase.

关键词： micromaser spectrum thermal-atom regime Kerr medium detuning

Three-dimensional numerical investigations of the laser-beam interactions in an undulator

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Chinese Physics C 2011年第3期35卷 308-312页

作者：邓海啸林唐宇颜俊王东戴志敏 Shanghai Institute of Applied Physics Chinese Academy of Sciences Department of Physics East China Normal University

Laser-beam interaction in an undulator is commonly suggested in the development of free electron laser （FEL） schemes. In this paper, a three-dimensional algorithm is developed to assist in laser-beam interaction simulation in an undulator, which is built on the basis of the fundamentals of electrodynamics, i.e. the electron’s behavior is determined by the magnetic field and the laser electric field in the time domain. On the basis of the algorithm, the detuning effect in a laser heater, the carrier envelope phase effect of a few-cycle laser in attosecond X-ray FEL schemes and output wavelength tuning in a high gain harmonic generation FEL are numerically discussed.

关键词： detuning laser-heater few-cycle laser carrier envelope phase