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arXiv 1111.3494cond-mat.dis-nnquant-ph
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格点上脏玻色子的玻璃到超流转变

Glass to superfluid transition in dirty bosons on a lattice

Julia Stasińska, Pietro Massignan, Michael Bishop, Jan Wehr, Anna Sanpera, Maciej Lewenstein

摘要:

我们研究了无序和相互作用之间的相互作用在一个玻色气体的随机局域杂质的存在下的晶格。我们比较了两种理论方法的性能,简单版本的多轨道Hartree-Fock和常见的Gross-Pitaevskii方法,显示了前者如何在弱相互作用的限制下,在超流分数很小的情况下,给出了一个非常好的近似基态。我们进一步严格证明了这类无序的基态d* 的分形维数在热力学极限下趋于物理维数。这使我们能够引入一个量,分数占用,它提供了从Lifshits到Bose玻璃的交叉的有见地的信息。最后,我们比较温度和相互作用的影响,突出的相似性和内在的差异。

英文摘要:

We investigate the interplay between disorder and interactions in a Bose gas on a lattice in presence of randomly localized impurities. We compare the performance of two theoretical methods, the simple version of multi-orbital Hartree-Fock and the common Gross-Pitaevskii approach, showing how the former gives a very good approximation to the ground state in the limit of weak interactions, where the superfluid fraction is small. We further prove rigorously that for this class of disorder the fractal dimension of the ground state d* tends to the physical dimension in the thermodynamic limit. This allows us to introduce a quantity, the fractional occupation, which gives insightful information on the crossover from a Lifshits to a Bose glass. Finally, we compare temperature and interaction effects, highlighting similarities and intrinsic differences.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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