title: Novel Topological Phase with a Zero Berry Curvature.
abstract: We present a two-dimensional (2D) lattice model that exhibits a nontrivial topological phase in the absence of the Berry curvature. Instead, the Berry connection provides the topological nontrivial phase in the model, whose integration over the momentum space, the so-called 2D Zak phase, yields a fractional wave polarization in each direction. These fractional wave polarizations manifest themselves as degenerated edge states with opposite parities in the model.
authors.affiliation: Department of Nanotechnology for Sustainable Energy, School of Science and Technology, Kwansei Gakuin University, Gakuen 2-1, Sanda 669-1337, Japan.
authors.forename: Feng
authors.initials: F
authors.lastname: Liu
authors.affiliation: Department of Naotechnology for Sustainable Energy, School of Science and Technology, Kwansei Gakuin University, Gakuen 2-1, Sanda 669-1337, Japan and National Institute for Materials Science (NIMS), Namiki 1-1, Tsukuba 305-0044, Japan.
authors.forename: Katsunori
authors.initials: K
authors.lastname: Wakabayashi