Moreo Adriana, Scalapino D J
Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966-1200, USA.
Phys Rev Lett. 2007 May 25;98(21):216402. doi: 10.1103/PhysRevLett.98.216402. Epub 2007 May 21.
Experiments on polarized fermion gases performed by trapping ultracold atoms in optical lattices allow the study of an attractive Hubbard model for which the strength of the on-site interaction is tuned by means of a Feshbach resonance. Using a well-known particle-hole transformation we discuss how results obtained for this system can be reinterpreted in the context of a doped repulsive Hubbard model. In particular, we show that the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state corresponds to the striped state of the two-dimensional doped positive U Hubbard model. We then use the results of numerical studies of the striped state to relate the periodicity of the FFLO state to the spin polarization. We also comment on the relationship of the d(x(2)-y(2)) superconducting phase of the doped 2D repulsive Hubbard model to a d-wave spin density wave state for the attractive case.
通过将超冷原子捕获在光学晶格中对极化费米子气体进行的实验，使得对一种吸引性哈伯德模型的研究成为可能，在该模型中，在位相互作用的强度通过费什巴赫共振来调节。利用一种著名的粒子-空穴变换，我们讨论了如何在掺杂排斥性哈伯德模型的背景下重新解释该系统所获得的结果。特别地，我们表明富尔德-费雷尔-拉金-奥夫钦尼科夫（FFLO）态对应于二维掺杂正U哈伯德模型的条纹态。然后，我们利用条纹态的数值研究结果，将FFLO态的周期性与自旋极化联系起来。我们还评论了掺杂二维排斥性哈伯德模型的d(x² - y²)超导相与吸引情形下的d波自旋密度波态之间的关系。
