title: Stable topological insulators achieved using high energy electron beams.
abstract: Topological insulators are potentially transformative quantum solids with metallic surface states which have Dirac band structure and are immune to disorder. Ubiquitous charged bulk defects, however, pull the Fermi energy into the bulk bands, denying access to surface charge transport. Here we demonstrate that irradiation with swift (∼2.5 MeV energy) electron beams allows to compensate these defects, bring the Fermi level back into the bulk gap and reach the charge neutrality point (CNP). Controlling the beam fluence, we tune bulk conductivity from p- (hole-like) to n-type (electron-like), crossing the Dirac point and back, while preserving the Dirac energy dispersion. The CNP conductance has a two-dimensional character on the order of ten conductance quanta and reveals, both in Bi2Te3 and Bi2Se3, the presence of only two quantum channels corresponding to two topological surfaces. The intrinsic quantum transport of the topological states is accessible disregarding the bulk size.
authors.affiliation: Department of Physics, The City College of New York, CUNY, New York, New York 10031, USA.
authors.forename: Lukas
authors.initials: L
authors.lastname: Zhao
authors.affiliation: Laboratoire des Solides Irradiés, École Polytechnique, CNRS, CEA, Université Paris-Saclay, 91128 Palaiseau cedex, France.
authors.forename: Marcin
authors.initials: M
authors.lastname: Konczykowski
authors.affiliation: Department of Physics, The City College of New York, CUNY, New York, New York 10031, USA.
authors.forename: Haiming
authors.initials: H
authors.lastname: Deng
authors.affiliation: Department of Physics, The City College of New York, CUNY, New York, New York 10031, USA.
authors.forename: Inna
authors.initials: I
authors.lastname: Korzhovska
authors.affiliation: Department of Physics, The City College of New York, CUNY, New York, New York 10031, USA.
authors.forename: Milan
authors.initials: M
authors.lastname: Begliarbekov
authors.affiliation: Department of Physics, The City College of New York, CUNY, New York, New York 10031, USA.
authors.forename: Zhiyi
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Laboratoire de Physique des Solides, CNRS, Université Paris-Saclay, Université Paris-Sud, 91405 Orsay, France.
authors.forename: Evangelos
authors.initials: E
authors.lastname: Papalazarou
authors.affiliation: Laboratoire de Physique des Solides, CNRS, Université Paris-Saclay, Université Paris-Sud, 91405 Orsay, France.
authors.forename: Marino
authors.initials: M
authors.lastname: Marsi
authors.affiliation: Laboratoire des Solides Irradiés, École Polytechnique, CNRS, CEA, Université Paris-Saclay, 91128 Palaiseau cedex, France.
authors.forename: Luca
authors.initials: L
authors.lastname: Perfetti
authors.affiliation: Institute of Electronic Materials Technology, 01-919 Warsaw, Poland.
authors.forename: Andrzej
authors.initials: A
authors.lastname: Hruban
authors.affiliation: Institute of Physics, Polish Academy of Sciences, 02-668 Warsaw, Poland.|Faculty of Physics, University of Warsaw, 00-681 Warsaw, Poland.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Wołoś
authors.affiliation: Department of Physics, The City College of New York, CUNY, New York, New York 10031, USA.
authors.forename: Lia
authors.initials: L
authors.lastname: Krusin-Elbaum
mesh_terms: D001729:Bismuth / Q000737:chemistry*; D004583:Electrons; D011789:Quantum Theory; D012666:Semiconductors; D055672:Static Electricity; D013499:Surface Properties; D013691:Tellurium / Q000737:chemistry*
chemical_list: C542787:bismuth telluride; D013691:Tellurium; D001729:Bismuth