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Stabilised bright solitons in Bose-Einstein condensates in an expulsive parabolic and complex potential

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Chinese physics B 2010年第7期19卷 73-78页

作者：张涛杨战营赵立臣岳瑞宏 department of physics Northwest University department of physics Ningbo University

The exact solitonic solutions of the one-dimensional nonlinear Schroedinger equation, which describes the dynamics of bright soliton in Bose-Einstein condensates with the time-dependent interaction in an expulsive parabolic and complex potential, are obtained by Darboux transformation. The results show that one can compress a bright soliton into an assumed peak of matter wave density by adusting the experimental parameter of the ratio of axial oscillation to radial oscillation or feeding parameter. Especially, when parameters satisfy the relation λ = 2γ the soliton is stable with time evolution without changing its shape and amplitude.

关键词： Bose-Einstein condensates one-dimensional Gross Pitaevskii equation bright soliton

Binding energy of the donor impurities in GaAs-Ga_(1-x)Al_xAs quantum well wires with Morse potential in the presence of electric and magnetic fields

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Chinese physics B 2016年第10期25卷 39-44页

作者： Esra Aciksoz Orhan Bayrak Asim Soylu department of physics Akdeniz University department of physics Nigde University

The behavior of a donor in the GaAs–GaAlAs quantum well wire represented by the Morse potential is examined within the framework of the effective-mass approximation. The donor binding energies are numerically calculated for with and without the electric and magnetic fields in order to show their influence on the binding energies. Moreover, how the donor binding energies change for the constant potential parameters(De, re, and a) as well as with the different values of the electric and magnetic field strengths is determined. It is found that the donor binding energy is highly dependent on the external electric and magnetic fields as well as parameters of the Morse potential.

关键词： Morse potential electric field magnetic field the donor atom quantum well wire

Effect of residual Doppler averaging on the probe absorption in cascade type system: A comparative study

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Chinese physics B 2018年第9期27卷 287-295页

作者： Suman Mondal Arindam Ghosh Khairul Islam Dipankar Bhattacharyya Amitava Bandyopadhyay department of physics Visva-Bharati department of physics Santipur College

Effect of residual Doppler averaging on the probe absorption in an alkali vapor medium in the presence of a coherent pump beam is studied analytically for the Ξ type system. A coherent probe field is assumed to connect the ground level with the intermediate level whereas a coherent control beam is supposed to act between the intermediate energy level and the uppermost level. Optical Bloch equations（OBE） for a three-level Ξ type system and a four-level Ξ type system are derived by using density matrix formalism. These equations are solved by an analytic method to determine the probe response, which not only depends on the wavelength difference between the control（pump） field and the probe field but shows substantially different features depending on whether the wavelength of the control field is greater than that of the probe field or the reverse. The effect of temperature on probe response is also shown. Enhancement in probe absorption and additional features are noticed under a strong probe limit at room temperature. The four-level Ξ type system has two ground levels and this leads to substantial modification in the simulated probe absorption as compared to the three-level system.

关键词： cascade type system density matrix method residual Doppler averaging electromagnetically induced transparency(EIT)

First-principles investigation of diffusion behaviours of H isotopes:From W(110) surface into bulk and in bulk W

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Chinese physics B 2012年第12期21卷 340-345页

作者：刘悦林卢苇高安远桂漓江张颖 department of physics Yantai University department of physics Beihang University

The diffusion behaviours of hydrogen （H）, deuterium （D）, and tritium （T） from W（110） surface into bulk and in bulk W are investigated using first-principles calculations combined with simplified models. The diffusion energy barrier is shown to be 1.87 eV from W（110） surface to the subsurface, along with a much reduced barrier of 0.06 eV for the reverse diffusion process. After H enters into the bulk, its diffusion energy barrier with quantum correction is 0.19 eV. In terms of the diffusion theory presented by Wert and Zener, the diffusion pre-exponential factor of H is calculated to be 1.57×10-7 m2.s-1, and it is quantitatively in agreement with the experimental value of 4.1×10-7 m2.s-1. Subsequently, according to mass dependence （√1/m） of H isotope effect, the diffusion pre-exponential factors of D and T are estimated to be 1.11×10-7 m2.s-1 and 0.91×10-7 m2.s-1, respectively.

关键词： tungsten (W) hydrogen isotopes diffusion

A new horizon for neuroscience:terahertz biotechnology in brain research

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Neural Regeneration Research 2025年第2期20卷 309-325页

作者： Zhengping Pu Yu Wu Zhongjie Zhu Hongwei Zhao Donghong Cui Shanghai Key Laboratory of Psychotic Disorders Shanghai Mental Health CenterShanghai Jiao Tong University School of MedicineShanghaiChina department of Psychiatry Kangci Hospital of JiaxingTongxiangZhejiang ProvinceChina Shanghai Synchrotron Radiation Facility Shanghai Advanced Research InstituteChinese Academy of SciencesShanghaiChina Key Laboratory of Interfacial physics and Technology Shanghai Institute of Applied PhysicsChinese Academy of ScienceShanghaiChina National Facility for Protein Science in Shanghai Shanghai Advanced Research InstituteChinese Academy of SciencesShanghaiChina

Terahertz biotechnology has been increasingly applied in various biomedical fields and has especially shown great potential for application in brain *** this article,we review the development of terahertz biotechnology and its applications in the field of *** evidence indicates promising prospects for the use of terahertz spectroscopy and terahertz imaging techniques in the diagnosis of amyloid disease,cerebrovascular disease,glioma,psychiatric disease,traumatic brain injury,and myelin *** vitro and animal experiments have also demonstrated the potential therapeutic value of terahertz technology in some neuropsychiatric *** the precise underlying mechanism of the interactions between terahertz electromagnetic waves and the biosystem is not yet fully understood,the research progress in this field shows great potential for biomedical noninvasive diagnostic and therapeutic ***,the biosafety of terahertz radiation requires further exploration regarding its two-sided efficacy in practical *** review demonstrates that terahertz biotechnology has the potential to be a promising method in the field of neuropsychiatry based on its unique advantages.

关键词： biological effect brain neuron neuropsychiatry neuroscience non-thermal effect terahertz imaging terahertz radiation terahertz spectroscopy terahertz technology

The q-analogues of two-mode squeezed states constructed by virtue of the IWOP technique

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Chinese physics B 2008年第8期17卷 2973-2978页

作者：孟祥国王继锁李洪奇 department of physics Liaocheng University department of physics Heze University

The q-analogues of two-mode squeezed states are introduced by virtue of deformation quantization methods and the technique of integration within an ordered product （IWOP） of operators. Some new completeness relations about these squeezed states composed of the bra and ket which are not mutually Hermitian conjugates are obtained. Furthermore, the antibunching effects of the two-mode squeezed vacuum state S＇s（τ） │00） are investigated. It is found that, in different ranges of the squeezed parameter τ, both modes of the state exhibit the antibunching effects and the two modes of the state are always nonclassical correlation.

关键词： q-analogue of two-mode squeezed state IWOP technique completeness relation anti-bunching effect

Field-assisted electron transport through a symmetric double-well structure with spin-orbit coupling and the Fano-resonance induced spin filtering

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Chinese physics B 2008年第7期17卷 2670-2677页

作者：张存喜聂一行梁九卿 department of physics and Institute of Theoretical physics Shanxi University department of physics Yanbei Normal Institute

We have investigated theoretically the field-driven electron-transport through a double-quantum-well semiconductor-heterostructure with spin-orbit coupling. The numerical results demonstrate that the transmission spectra are divided into two sets due to the bound-state level-splitting and each set contains two asymmetric resonance peaks which may be selectively suppressed by changing the difference in phase between two driving fields. When the phase difference changes from 0 to π, the dip of asymmetric resonance shifts from one side of resonance peak to the other side and the asymmetric Fano resonance degenerates into the symmetric Breit-Wigner resonance at a critical value of phase difference. Within a given range of incident electron energy, the spin polarization of transmission current is completely governed by the phase difference which may be used to realize the tunable spin filtering.

关键词： Fano effect Floquet channel spin-orbit coupling

Optimal entropy squeezing sudden generation and its control for an effective two-level moving atom entanglement with the two-mode coherent fields

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Chinese physics B 2009年第6期18卷 2307-2313页

作者：刘小娟周元俊方卯发 department of physics Hunan University of Science and Technology department of physics Hunan Normal University department of physics Nanjing University

From the viewpoint of quantum information, this paper proposes a concept and a definition of the atomic optimal entropy squeezing sudden generation （AOESSG） for the system of an effective two-level moving atom which entangles with the two-mode coherent fields. It also researches the relationship between the AOESSG and entanglement sudden death of the atom-fields, and discusses the influences of atomic initial state on the AOESSG and obtains the system parameter which controls the AOESSG.

关键词： optical entropy squeezing sudden generation effective two-level moving atom entanglement sudden death

Enhanced structural and magnetic properties of microwave sintered Li–Ni–Co ferrites prepared by sol–gel method

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Chinese physics B 2019年第2期28卷 358-362页

作者： NANDeibam Nilima M Maisnam Sumitra Phanjoubam department of physics Oriental College department of physics Oriental CollegeTakyel department of physics Manipur University

The properties of lithium ferrites are very sensitive to chemical composition, synthesis method, and sintering techniques. Li–Ni–Co ferrites with compositional formula Li_(0.45-0.5x)Ni_(0.1)Co_xFe_(2.45-0.5x)O_4, where 0.00 ≤ x ≤ 0.1 in steps of 0.02 were prepared by chemical sol–gel method and sintered by microwave sintering technique. The x-ray diffraction patterns confirmed the formation of single phase with spinel structure in all the samples. The structural parameter *** constant, crystallite size, and x-ray density for these samples were studied and compared with those measured from samples of similar composition prepared by the sol–gel method and sintered by conventional sintering technique. Enhancement in the magnetic properties like Curie temperature, hysteresis parameters was observed by employing sol–gel synthesis combined with microwave sintering. The results obtained and mechanisms involved are discussed in the paper.

关键词： lithium ferrites sol–gel chemistry magnetic properties x-ray diffraction