title: Engineering and Probing Topological Properties of Dirac Semimetal Films by Asymmetric Charge Transfer.
abstract: Dirac semimetals (DSMs) have topologically robust three-dimensional Dirac (doubled Weyl) nodes with Fermi-arc states. In heterostructures involving DSMs, charge transfer occurs at the interfaces, which can be used to probe and control their bulk and surface topological properties through surface-bulk connectivity. Here we demonstrate that despite a band gap in DSM films, asymmetric charge transfer at the surface enables one to accurately identify locations of the Dirac-node projections from gapless band crossings and to examine and engineer properties of the topological Fermi-arc surface states connecting the projections, by simulating adatom-adsorbed DSM films using a first-principles method with an effective model. The positions of the Dirac-node projections are insensitive to charge transfer amount or slab thickness except for extremely thin films. By varying the amount of charge transfer, unique spin textures near the projections and a separation between the Fermi-arc states change, which can be observed by gating without adatoms.
authors.affiliation: Department of Physics, Virginia Tech , Blacksburg, Virginia 24061, United States.
authors.forename: John W
authors.identifier: 0000-0003-1595-3851
authors.initials: JW
authors.lastname: Villanova
authors.affiliation: Department of Physics, Virginia Tech , Blacksburg, Virginia 24061, United States.
authors.forename: Edwin
authors.initials: E
authors.lastname: Barnes
authors.affiliation: Department of Physics, Virginia Tech , Blacksburg, Virginia 24061, United States.
authors.forename: Kyungwha
authors.initials: K
authors.lastname: Park
mesh_terms: D001729:Bismuth / Q000737:chemistry; D003460:Crystallization; D004553:Electric Conductivity; D008670:Metals / Q000737:chemistry*; D055585:Physical Phenomena; D012964:Sodium / Q000737:chemistry; D013499:Surface Properties
chemical_list: D008670:Metals; D012964:Sodium; D001729:Bismuth
keywords: DFT; Dirac and Weyl semimetal; Weyl nodes; charge transfer; heterostructures; surface Fermi arcs