论文标题
量子蒙特卡洛模拟BEC IMBRITITY隧道
Quantum Monte Carlo simulation of BEC-impurity tunneling
论文作者
论文摘要
极性隧穿是一个以不同能量尺度为特征的问题的突出例子，标准量子蒙特卡洛方法面临速度放缓的问题。我们提出了一种新的量子隧道蒙特卡洛（QTMC）方法，该方法没有此问题，可用于广泛的隧道现象。我们将其应用于研究与一维玻色凝结物相互作用的杂质，并同时被困在外部双孔电势中。我们的方案适用于粒子和冷凝物之间的任意耦合，同时允许对隧道效应进行描述。我们分别发现了与声子辅助的隧道和杂质的自我捕获的两个不同的准粒子峰，这些峰和杂质的自我捕获是对模型的系统的交叉策略。当耦合强度提高时，我们观察和分析峰的重量和光谱位置的变化（或同样是准颗粒的有效质量）。讨论了使用冷原子可能实现的实验实现。
Polaron tunneling is a prominent example of a problem characterized by different energy scales, for which the standard quantum Monte Carlo methods face a slowdown problem. We propose a new quantum-tunneling Monte Carlo (QTMC) method which is free from this issue and can be used for a wide range of tunneling phenomena. We apply it to study an impurity interacting with a one-dimensional Bose-Einstein condensate and simultaneously trapped in an external double-well potential. Our scheme works for an arbitrary coupling between the particle and condensate and, at the same time, allows for an account of tunneling effects. We discover two distinct quasi-particle peaks associated, respectively, with the phonon-assisted tunneling and the self-trapping of the impurity, which are in a crossover regime for the system modeled. We observe and analyze changes in the weights and spectral positions of the peaks (or, equally, effective masses of the quasi-particles) when the coupling strength is increased. Possible experimental realizations using cold atoms are discussed.
