Theoretische Physik, ETH Zurich, 8093 Zurich, Switzerland.
Phys Rev Lett. 2012 Nov 16;109(20):206401. doi: 10.1103/PhysRevLett.109.206401. Epub 2012 Nov 13.
We calculate the phase diagram of the Bose-Fermi Hubbard model on the 3d cubic lattice at fermionic half filling and bosonic unit filling by means of single-site dynamical mean-field theory. For fast bosons, this is equivalent to the Cooper problem in which the bosons can induce s-wave pairing between the fermions. We also find miscible superfluid and canted supersolid phases depending on the interspecies coupling strength. In contrast, slow bosons favor fermionic charge density wave structures for attractive fermionic interactions. These competing instabilities lead to a rich phase diagram within reach of cold gas experiments.
我们通过单站点动力学平均场理论计算了费米子半填充和玻色子单位填充的 3d 立方晶格上玻色-费米 Hubbard 模型的相图。对于快速玻色子，这相当于 Cooper 问题，其中玻色子可以在费米子之间诱导 s 波配对。我们还发现了根据种间耦合强度而定的混溶性超流和倾斜超固态相。相比之下，对于吸引的费米子相互作用，慢速玻色子有利于费米子电荷密度波结构。这些竞争的不稳定性导致了冷气体实验可及的丰富相图。
