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arXiv 0907.5436cond-mat.quant-gas
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低维弱相互作用玻色气体:非普适状态方程

Low-dimensional weakly interacting Bose gases: non-universal equations of state

G. E. Astrakharchik, J. Boronat, I. L. Kurbakov, Yu. E. Lozovik, F. Mazzanti

摘要:

分析了低维玻色子系统的零温度状态方程。在稀相区,状态方程在气体参数方面是普适的,即对于具有相同s波散射长度值的不同势,状态方程是相同的。本文报道了一维和二维系统的通用状态方程的级数展开式.我们建议使用的概念,能量依赖的s-波散射长度获得的能量展开的非通用条款的估计。我们测试这种方法进行比较,完全可解的一维问题,并发现生成的条款有正确的结构。通过与蒙特卡罗模拟结果的比较,分析了该方法对二维系统的适用性。对非普适行为的预测是定性正确的,并适当地估计了偏离普适状态方程的密度。最后,讨论了在实验中观察非普适项的可能性。

英文摘要:

The zero-temperature equation of state is analyzed in low-dimensional bosonic systems. In the dilute regime the equation of state is universal in terms of the gas parameter, i.e. it is the same for different potentials with the same value of the s-wave scattering length. Series expansions of the universal equation of state are reported for one- and two- dimensional systems. We propose to use the concept of energy-dependent s-wave scattering length for obtaining estimations of non-universal terms in the energy expansion. We test this approach by making a comparison to exactly solvable one-dimensional problems and find that the generated terms have the correct structure. The applicability to two-dimensional systems is analyzed by comparing with results of Monte Carlo simulations. The prediction for the non-universal behavior is qualitatively correct and the densities, at which the deviations from the universal equation of state become visible, are estimated properly. Finally, the possibility of observing the non-universal terms in experiments with trapped gases is also discussed.

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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