Fermi gases with imaginary mass imbalance and the sign problem in Monte Carlo calculations
Fermi gases with imaginary mass imbalance and the sign problem in Monte Carlo calculations
复制标题
具有虚质量不平衡的费米气体和蒙特卡罗计算中的符号问题
DOI：
10.1088/0954-3899/41/5/055110
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发表时间：
2014
期刊：
影响因子：
--
通讯作者：
J. E. Drut
中科院分区：
文献类型：
--
作者：
D. Roscher;J. Braun;J. W. Chen;J. E. Drut
费米气体在强耦合区对多体方法来说具有内在的挑战性。虽然已经取得了进展，分析，定量结果需要从头算数值方法，如蒙特-卡罗（MC）计算。然而，质量不平衡和自旋不平衡的气体，由于臭名昭著的符号问题，无法进入MC计算。对于有限的自旋不平衡，这个问题可以通过虚极化和解析延拓来解决，这样就可以得到大部分的相图。我们建议将这种策略应用于质量不平衡的情况下，这开辟了可能性，研究与MC计算相关联的相图。我们进行了第一次平均场分析，这表明零温度的研究，以及检测潜在的（三）临界点，是可行的。
Fermi gases in strongly coupled regimes are inherently challenging for many-body methods. Although progress has been made analytically, quantitative results require ab initio numerical approaches, such as Monte-Carlo (MC) calculations. However, mass-imbalanced and spin-imbalanced gases are not accessible to MC calculations due to the infamous sign problem. For finite spin imbalance, the problem can be circumvented using imaginary polarizations and analytic continuation, and large parts of the phase diagram then become accessible. We propose to apply this strategy to the mass-imbalanced case, which opens up the possibility to study the associated phase diagram with MC calculations. We perform a first mean-field analysis which suggests that zero-temperature studies, as well as detecting a potential (tri) critical point, are feasible.