Fulde-Ferrell Superfluids in Degenerate Fermi Gases with Synthetic Gauge Fields

Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) phase was first predicted in two-dimensional superconductors about 50 years ago, but so far unambiguous experimental evidence is still lacking. The recently experimentally realized spin-imbalanced Fermi gases may potentially unveil this elusive state, but they require very stringent experimental conditions. In this talk, I will discuss a new route for generating stable FF phases through single particle band dispersion engineering using the recently experimentally generated synthetic gauge fields, such as artificial spin-orbit coupling or band hybridization in driven optical lattices. I will show that such FF superfluids can support topological quantum excitations such as Majorana and Weyl fermions.\\[4pt] [1] Z. Zheng, M. Gong, X. Zhou, C. Zhang, and G.-C. Guo, Phys. Rev. A 87, 031602 (2013).\\[0pt] [2] C. Qu, Z. Zheng, M. Gong, Y. Xu, L. Mao, X. Zou, G.-C. Guo, C. Zhang, Nature Communications 4, 2710 (2013).\\[0pt] [3] Y. Xu, C. Qu, M. Gong, C. Zhang, Phys. Rev. A 89, 013607 (2014).\\[0pt] [4] Y. Xu, R. Chu, C. Zhang, Phys. Rev. Lett. 112, 136402 (2014) Editors' Suggestions\\[0pt] [5] C. Qu, M. Gong, C. Zhang, Phys. Rev. A 89, 053618 (2014).\\[0pt] [6] Y. Xu, C. Zhang, arXiv:1407.3483\\[0pt] [7] Z. Zheng, C. Qu, X. Zou, C. Zhang, arXiv:1408.5824\\[0pt] [8] Z. Zheng, C. Qu, X. Zou, C. Zhang, Spin imbalanced Fulde-Ferrell superfluids in 3D driven fermionic optical lattices, in preparation.