PIMC study of spin-polarized 1D trapped fermions with strong attractive contact interaction

Spin imbalance in a trapped one-dimensional gas of ${}^6$Li atoms ($F=1/2$) is studied with continuous-space path-integral Monte Carlo simulation. This follows closely the experiment of Liao et al. [1], which aims to confirm the existence of the FFLO pairing predicted from the Bethe ansatz [2,3] and DMRG [4,5]. Algorithmic improvements [6] to the configuration-space sampling efficiency of a previous work [7] is made in order to explore the conditions where the attractive contact interaction between unlike-spin atoms can be stronger than in the previously accessible. Signatures of FFLO pairing is looked for in the pair momentum distribution.\\ \\ $\left[1\right]$ Y.-A. Liao et al., Nature \textbf{467}, 567 (2010).\\ $\left[2\right]$ X.-W. Guan et al., Phys. Rev. B \textbf{76}, 085120 (2007).\\ $\left[3\right]$ E. Zhao et al., Phys. Rev. Lett. \textbf{103}, 140404 (2009).\\ $\left[4\right]$ M. Rizzi et al., Phys. Rev. B \textbf{77}, 245105 (2008).\\ $\left[5\right]$ F. Heidrich-Meisner et al., Phys. Rev. A \textbf{81}, 023629 (2010).\\ $\left[6\right]$ M. Boninsegni et al. Phys. Rev. E, \textbf{74}, 036701, (2006).\\ $\left[7\right]$ M. Casula et al. Phys. Rev. A, \textbf{78}, 033607, (2008).