title: Structured Weyl Points in Spin-Orbit Coupled Fermionic Superfluids.
abstract: We demonstrate that a Weyl point, widely examined in 3D Weyl semimetals and superfluids, can develop a pair of nondegenerate gapless spheres. Such a bouquet of two spheres is characterized by three distinct topological invariants of manifolds with full energy gaps, i.e., the Chern number of a 0D point inside one developed sphere, the winding number of a 1D loop around the original Weyl point, and the Chern number of a 2D surface enclosing the whole bouquet. We show that such structured Weyl points can be realized in the superfluid quasiparticle spectrum of a 3D degenerate Fermi gas subject to spin-orbit couplings and Zeeman fields, which supports Fulde-Ferrell superfluids as the ground state.
authors.affiliation: Department of Physics, University of Texas at Dallas, Richardson, Texas 75080, USA.
authors.forename: Yong
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Department of Physics, University of Texas at Dallas, Richardson, Texas 75080, USA.
authors.forename: Fan
authors.initials: F
authors.lastname: Zhang
authors.affiliation: Department of Physics, University of Texas at Dallas, Richardson, Texas 75080, USA.
authors.forename: Chuanwei
authors.initials: C
authors.lastname: Zhang