标题： 强配对费米子的辅助场量子蒙特卡罗方法 显示英文标题

标题： Auxiliary Field quantum Monte Carlo for Strongly Paired Fermions

摘要： 我们证明，包含BCS重要性函数显著提高了辅助场方法在强配对情况下的效率。 我们计算了在单位极限下无极化费米气体的基态能量，最多包含66个粒子和最多$27^3$个格点。 该方法没有费米子符号问题，并且在通用参数$\xi$上获得了精确的结果。 几种针对单位极限但具有不同有效范围的动能形式，在误差范围内外推到相同的连续极限。 不同相互作用的有限有效范围结果与费米动量乘以有效范围的线性项一致。 本文所述的新方法在超流冷原子系统以及当配对重要时的电子和核结构中将有许多应用。 显示英文摘要

摘要： We demonstrate that the inclusion of a BCS importance function dramatically increases the efficiency of the auxiliary field method for strong pairing. We calculate the ground-state energy of an unpolarized fermi gas at unitarity with up to 66 particles and lattices of up to $27^3$ sites. The method has no fermion sign problem, and an accurate result is obtained for the universal parameter $\xi$. Several different forms of the kinetic energy adjusted to the unitary limit but with different effective ranges extrapolate to the same continuum limit within error bars. The finite effective range results for different interactions are consistent with a linear term proportional to the Fermi momentum times the effective range. The new method described herein will have many applications in superfluid cold atom systems and in both electronic and nuclear structures when pairing is important.