6 research outputs found

    Energy band structure and intrinsic coherent properties in two weakly linked Bose Einstein Condensates

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    The energy band structure and energy splitting due to quantum tunneling in two weakly linked Bose-Einstein condensates were calculated by using the instanton method. The intrinsic coherent properties of Bose Josephson junction were investigated in terms of energy splitting. For EC/EJâ‰Ș1E_{C}/E_{J}\ll 1, the energy splitting is small and the system is globally phase coherent. In the opposite limit, EC/EJ≫1E_{C}/E_{J}\gg 1, the energy splitting is large and the system becomes a phase dissipation. Our reslults suggest that one should investigate the coherence phenomna of BJJ in proper condition such as EC/EJ∌1E_{C}/E_{J}\sim 1.Comment: to appear in Phys. Rev. A, 2 figure

    Edge magnetoplasmons in periodically modulated structures

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    We present a microscopic treatment of edge magnetoplasmons (EMP's) within the random-phase approximation for strong magnetic fields, low temperatures, and filling factor Μ=1(2)\nu =1(2), when a weak short-period superlattice potential is imposed along the Hall bar. The modulation potential modifies both the spatial structure and the dispersion relation of the fundamental EMP and leads to the appearance of a novel gapless mode of the fundamental EMP. For sufficiently weak modulation strengths the phase velocity of this novel mode is almost the same as the group velocity of the edge states but it should be quite smaller for stronger modulation. We discuss in detail the spatial structure of the charge density of the renormalized and the novel fundamental EMP's.Comment: 8 pages, 4 figure
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