Monte Carlo study of strongly interacting two-dimensional Fermi gases
Monte Carlo study of strongly interacting two-dimensional Fermi gases
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DOI：
10.1103/physreva.93.023602
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发表时间：
2015-11
期刊：
影响因子：
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通讯作者：
Alexander Galea;Hillary Dawkins;S. Gandolfi;A. Gezerlis
中科院分区：
文献类型：
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作者：
Alexander Galea;Hillary Dawkins;S. Gandolfi;A. Gezerlis
超冷原子费米气体一直是一个热门的研究课题，最近引起了人们对二维(2D)气体的关注。在这项工作中，我们对二维费米强相互作用气体进行了T=0从头算扩散的蒙特卡罗计算。我们首先回顾一下有限大小的系统，以及与热力学极限的联系。然后，我们说明了相关的二维散射物理和波函数的性质。然后我们给出了在玻色-爱因斯坦凝聚(BEC)和Bardeen-Cooper-Schrieffer(BCS)区域之间强耦合交叉的能量结果。我们的BEC-BCS交叉的能量结果被参数化，以产生一个状态方程，该方程用于确定Tan的接触。我们与其他微观结果进行了详细的比较。最后，我们从变分优化的多体波函数出发，计算了强耦合区域内一定相互作用强度范围内的配对能隙。
Ultracold atomic Fermi gases have been a popular topic of research, with attention being paid recently to two-dimensional (2D) gases. In this work, we perform T=0 ab initio diffusion Monte Carlo calculations for a strongly interacting two-component Fermi gas confined to two dimensions. We first go over finite-size systems and the connection to the thermodynamic limit. After that, we illustrate pertinent 2D scattering physics and properties of the wave function. We then show energy results for the strong-coupling crossover, in between the Bose-Einstein Condensation (BEC) and Bardeen-Cooper-Schrieffer (BCS) regimes. Our energy results for the BEC-BCS crossover are parametrized to produce an equation of state, which is used to determine Tan's contact. We carry out a detailed comparison with other microscopic results. Finally, we calculate the pairing gap for a range of interaction strengths in the strong coupling regime, following from variationally optimized many-body wave functions.