Engineering and probing topological properties of Dirac semimetal films by asymmetric charge transfer

Datum: 5 oktober 2016

Locatie: UAntwerpen, Campus Groenenborger, Building U, room U.241 - Groenenborgerlaan 171 - 2020 Antwerpen (route: UAntwerpen, Campus Groenenborger)

Tijdstip: 16 - 17 uur

Organisatie / co-organisatie: Condensed Matter Theory group

Korte beschrijving: Physics Department seminar presented by Prof Kyungwha Park from Virginia Tech University

Abstract

Dirac semimetals (DSMs) have topologically robust three-dimensional (doubled Weyl) nodes with Fermi-arc states. In heterostructures involving DSMs, charge transfer may occur at the interfaces, which can be used to probe and control their bulk and surface topological properties through surface-bulk connectivity. 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.

Physics department seminar presented by Prof.  Kyungwha Park from Virginia Tech University, USA.

 



Contact e-mail: lucian.covaci@uantwerpen.be

Url: http://cmt.uantwerpen.be