Combescot R, Recati A, Lobo C, Chevy F
Laboratoire de Physique Statistique, Ecole Normale Supérieure, 24 rue Lhomond, 75231 Paris Cedex 05, France.
Phys Rev Lett. 2007 May 4;98(18):180402. doi: 10.1103/PhysRevLett.98.180402. Epub 2007 May 1.
We consider the problem of a single downward arrow atom in the presence of a Fermi sea of upward arrow atoms, in the vicinity of a Feshbach resonance. We calculate the chemical potential and the effective mass of the downward arrow atom using two simple approaches: a many-body variational wave function and a T-matrix approximation. These two methods lead to the same results and are in good agreement with existing quantum Monte Carlo calculations performed at unitarity and, in one dimension, with the known exact solution. Surprisingly, our results suggest that, even at unitarity, the effect of interactions is fairly weak and can be accurately described using single particle-hole excitations. We also consider the case of unequal masses.
我们考虑在费什巴赫共振附近，存在向上箭头原子的费米海时单个向下箭头原子的问题。我们使用两种简单方法计算向下箭头原子的化学势和有效质量：多体变分波函数和T矩阵近似。这两种方法得出相同的结果，并且与在幺正性条件下进行的现有量子蒙特卡罗计算结果以及一维情况下的已知精确解非常吻合。令人惊讶的是，我们的结果表明，即使在幺正性条件下，相互作用的影响也相当微弱，并且可以使用单粒子 - 空穴激发来准确描述。我们还考虑了质量不相等的情况。
