Imaginary polarization as a way to surmount the sign problem in ab initio calculations of spin-imbalanced Fermi gases.
Imaginary polarization as a way to surmount the sign problem in ab initio calculations of spin-imbalanced Fermi gases.
复制标题
虚极化作为克服自旋不平衡费米气体从头算中符号问题的一种方法
DOI：
10.1103/physrevlett.110.130404
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发表时间：
2013
影响因子：
8.6
通讯作者：
Y. D. Tsai
中科院分区：
文献类型：
--
作者：
J. Braun;J. W. Chen;J. Deng;J. E. Drut;B. Friman;C. T. Ma;Y. D. Tsai
从超冷原子到量子色动力学，强相互作用费米子的可靠的从头计算研究需要数值方法，通常是某种形式的量子蒙特卡罗计算。不幸的是，在有限密度（自旋极化）的（非）相对论系统通常有一个符号问题，使得这些从头计算是不切实际的。然而，众所周知，在相对论的情况下，假设数据可以解析地延拓到真实的轴，虚化学势可以解决这个问题。这对非相对论系统可行吗？相图中有趣的特征是否可以用这种方式来理解？通过引入复化学势，对于真实的总粒子数和虚极化，避免了非相对论情况下的符号问题。为了首次回答上述问题，我们对具有虚极化的自旋费米子的有限温度相图进行了平均场研究。
From ultracold atoms to quantum chromodynamics, reliableab initiostudies of strongly interacting fermions require numerical methods, typically in some form of quantum Monte Carlo calculation. Unfortunately, (non)relativistic systems at finite density (spin polarization) generally have a sign problem, such that thoseab initiocalculations are impractical. It is well-known, however, that in the relativistic case imaginary chemical potentials solve this problem, assuming the data can be analytically continued to the real axis. Is this feasible for nonrelativistic systems? Are the interesting features of the phase diagram accessible in this manner? By introducing complex chemical potentials, for real total particle number and imaginary polarization, the sign problem is avoided in the nonrelativistic case. To give a first answer to the above questions, we perform a mean-field study of the finite-temperature phase diagram of spin-fermions with imaginary polarization.