Zero-density-limit extrapolation of the superfluid transition temperature in a unitary atomic Fermi gas on a lattice
Zero-density-limit extrapolation of the superfluid transition temperature in a unitary atomic Fermi gas on a lattice
复制标题
晶格上酉原子费米气体超流体转变温度的零密度极限外推
DOI：
10.1103/physreva.86.023610
复制
发表时间：
2011-09
影响因子：
2.9
通讯作者：
Chen, Qijin
中科院分区：
文献类型：
--
作者：
Chen, Qijin
使用配对涨落理论，研究了具有吸引力的现场相互作用的三维各向同性晶格上的酉费米气体的超流体转变温度 $T_c$ 作为密度 $n$ 的函数，从半填充到每晶胞 $5.0\times 10^{-7}$。我们表明，除了在非常低的密度 ($n^{1/3} <0.2$) 下（其中 $T_c/E_F$ 在 $n^{1/3}$ 中呈线性）之外，$T_c/E_F$ 对 $n^{1/3}$ 表现出显着的高阶非线性依赖性。因此，使用中间密度的结果（例如典型的量子蒙特卡罗模拟）进行线性外推会导致 $T_c/E_F$ 的零密度极限显着低估。我们的结果 $T_c/E_F=0.256$（在 $n=0$ 处）受到粒子孔波动和不相干单粒子自能校正的影响。
The superfluid transition temperature $T_c$ of a unitary Fermi gas on a three-dimensional isotropic lattice with an attractive on-site interaction is investigated as a function of density $n$, from half filling down to $5.0\times 10^{-7}$ per unit cell, using a pairing fluctuation theory. We show that except at very low densities ($n^{1/3} <0.2$), where $T_c/E_F$ is linear in $n^{1/3}$, $T_c/E_F$ exhibits significant higher order nonlinear dependence on $n^{1/3}$. Therefore, linear extrapolation using results at intermediate densities such as in typical quantum Monte Carlo simulations leads to a significant underestimate of the zero density limit of $T_c/E_F$. Our result, $T_c/E_F=0.256$, at $n=0$ is subject to reduction from particle-hole fluctuations and incoherent single particle self energy corrections.