Nodal Topological Phases in s-wave Superfluid of Ultracold Fermionic Gases  

作　　者：Bei-Bing Huang Xiao-Sen Yang 黄备兵;杨孝森(Department of Physics Yancheng Institute of Technology,Yancheng 224051,China;Department of Physics Jiangsu University,Zhejiang 212013,China)

机构地区：[1]Department of Physics, Yancheng Institute of Technology, Yancheng 224051, China [2]Department of Physics, Jiangsu University, Zhenjiang 212013, China

出　　处：《Communications in Theoretical Physics》2018年第2期137-142,共6页理论物理通讯（英文版）

基　　金：Supported by National Natural Science Foundation of China under Grant Nos.11547047 and 11504143

摘　　要：The gapless Weyl superfluid has been widely studied in the three-dimensional ultracold fermionic superfluid. In contrast to Weyl superfluid, there exists another kind of gapless superfluid with topologically protected nodal lines, which can be regarded as the superttuid counterpart of nodal line semimetal in the condensed matter physics, just as Weyl superfluid with Weyl semimetal. In this paper we study the ground states of the cold fermionic gases in cubic optical lattices with one-dimensional spin-orbit coupling and transverse Zeeman field and map out the topological phase diagram of the system. We demonstrate that in addition to a fully gapped topologically trivial phase, some different nodal line superfluid phases appear when the Zeeman field is adjusted. The presence of topologically stable nodal lines implies the dispersionless zero-energy fiat band in a finite region of the surface Brillouin zone. Experimentally these nodal line superfluid states can be detected via the momentum-resolved radio-frequency spectroscopy. The nodal line topological superfluid provide fertile grounds for exploring exotic quantum matters in the context of ultraeold atoms.

关 键 词：gapless topological superfluid nodal line surface flat band 

分 类 号：O469[理学—凝聚态物理]