title: Surface to bulk Fermi arcs via Weyl nodes as topological defects.
abstract: A hallmark of Weyl semimetal is the existence of surface Fermi arcs. An intriguing question is what determines the connectivity of surface Fermi arcs, when multiple pairs of Weyl nodes are present. To answer this question, we show that the locations of surface Fermi arcs are predominantly determined by the condition that the Zak phase integrated along the normal-to-surface direction is . The Zak phase can reveal the peculiar topological structure of Weyl semimetal directly in the bulk. Here, we show that the winding of the Zak phase around each projected Weyl node manifests itself as a topological defect of the Wannier-Stark ladder, energy eigenstates under an electric field. Remarkably, this leads to bulk Fermi arcs, open-line segments in the bulk spectra. Bulk Fermi arcs should exist in conjunction with surface counterparts to conserve the Weyl fermion number under an electric field, which is supported by explicit numerical evidence.
authors.affiliation: School of Physics, Korea Institute for Advanced Study, Seoul 02455, Korea.
authors.forename: Kun Woo
authors.initials: KW
authors.lastname: Kim
authors.affiliation: School of Physics, Korea Institute for Advanced Study, Seoul 02455, Korea.|Quantum Universe Center, Korea Institute for Advanced Study, Seoul 02455, Korea.
authors.forename: Woo-Ram
authors.initials: WR
authors.lastname: Lee
authors.affiliation: School of Physics, Korea Institute for Advanced Study, Seoul 02455, Korea.|Department of Physics and Centre for Quantum Materials, University of Toronto, Toronto, Ontario, Canada M5S 1A7.
authors.forename: Yong Baek
authors.initials: YB
authors.lastname: Kim
authors.affiliation: School of Physics, Korea Institute for Advanced Study, Seoul 02455, Korea.|Quantum Universe Center, Korea Institute for Advanced Study, Seoul 02455, Korea.
authors.forename: Kwon
authors.initials: K
authors.lastname: Park