Mathey L, Tsai S-W, Neto A H Castro
Physics Department, Harvard University, Cambridge, Massachusetts 02138, USA.
Phys Rev Lett. 2006 Jul 21;97(3):030601. doi: 10.1103/PhysRevLett.97.030601. Epub 2006 Jul 19.
Using a functional renormalization group approach we study the zero temperature phase diagram of two-dimensional Bose-Fermi mixtures of ultracold atoms in optical lattices, in the limit when the velocity of bosonic condensate fluctuations is much larger than the Fermi velocity. For spin-1/2 fermions we obtain a phase diagram, which shows a competition of pairing phases of various orbital symmetry (s, p, and d) and antiferromagnetic order. We determine the value of the gaps of various phases close to half filling, and identify subdominant orders as well as short-range fluctuations from the renormalization group flow. For spinless fermions we find that p-wave pairing dominates the phase diagram.
我们使用泛函重整化群方法，研究光学晶格中超冷原子的二维玻色 - 费米混合物在零温度下的相图，这里取玻色凝聚体涨落速度远大于费米速度的极限情况。对于自旋为1/2的费米子，我们得到了一个相图，该相图展示了各种轨道对称性（s、p和d）的配对相以及反铁磁序之间的竞争。我们确定了接近半填充时各相能隙的值，并从重整化群流中识别出次主导序以及短程涨落。对于无自旋费米子，我们发现p波配对在相图中占主导。
