title: Tuning a Schottky barrier in a photoexcited topological insulator with transient Dirac cone electron-hole asymmetry.
abstract: The advent of Dirac materials has made it possible to realize two-dimensional gases of relativistic fermions with unprecedented transport properties in condensed matter. Their photoconductive control with ultrafast light pulses is opening new perspectives for the transmission of current and information. Here we show that the interplay of surface and bulk transient carrier dynamics in a photoexcited topological insulator can control an essential parameter for photoconductivity-the balance between excess electrons and holes in the Dirac cone. This can result in a strongly out of equilibrium gas of hot relativistic fermions, characterized by a surprisingly long lifetime of more than 50 ps, and a simultaneous transient shift of chemical potential by as much as 100 meV. The unique properties of this transient Dirac cone make it possible to tune with ultrafast light pulses a relativistic nanoscale Schottky barrier, in a way that is impossible with conventional optoelectronic materials.
authors.affiliation: Laboratoire de Physique des Solides, CNRS-UMR 8502, Université Paris-Sud, Orsay F-91405, France.
authors.forename: M
authors.initials: M
authors.lastname: Hajlaoui
authors.affiliation: Laboratoire de Physique des Solides, CNRS-UMR 8502, Université Paris-Sud, Orsay F-91405, France.
authors.forename: E
authors.initials: E
authors.lastname: Papalazarou
authors.affiliation: Laboratoire de Physique des Solides, CNRS-UMR 8502, Université Paris-Sud, Orsay F-91405, France.
authors.forename: J
authors.initials: J
authors.lastname: Mauchain
authors.affiliation: Laboratoire des Solides Irradiés, Ecole Polytechnique-CEA/DSM-CNRS UMR 7642, Palaiseau 91128, France.
authors.forename: L
authors.initials: L
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authors.affiliation: UR1-CNRS/Synchrotron SOLEIL, Saint Aubin BP 48, Gif-sur-Yvette F-91192, France.
authors.forename: A
authors.initials: A
authors.lastname: Taleb-Ibrahimi
authors.affiliation: Laboratoire de Physique des Solides, CNRS-UMR 8502, Université Paris-Sud, Orsay F-91405, France.
authors.forename: F
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authors.affiliation: Laboratoire de Physique des Solides, CNRS-UMR 8502, Université Paris-Sud, Orsay F-91405, France.
authors.forename: M
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authors.lastname: Monteverde
authors.affiliation: Laboratoire de Physique des Solides, CNRS-UMR 8502, Université Paris-Sud, Orsay F-91405, France.
authors.forename: P
authors.initials: P
authors.lastname: Auban-Senzier
authors.affiliation: Laboratoire de Physique des Solides, CNRS-UMR 8502, Université Paris-Sud, Orsay F-91405, France.
authors.forename: C R
authors.initials: CR
authors.lastname: Pasquier
authors.affiliation: Laboratoire d'Optique Appliquée, ENSTA ParisTech, CNRS, Ecole Polytechnique, 91761 Palaiseau, France.
authors.forename: N
authors.initials: N
authors.lastname: Moisan
authors.affiliation: Laboratoire d'Optique Appliquée, ENSTA ParisTech, CNRS, Ecole Polytechnique, 91761 Palaiseau, France.
authors.forename: D
authors.initials: D
authors.lastname: Boschetto
authors.affiliation: Department of Physics, Princeton University, Princeton, New Jersey 08544, USA.
authors.forename: M
authors.initials: M
authors.lastname: Neupane
authors.affiliation: Department of Physics, Princeton University, Princeton, New Jersey 08544, USA.
authors.forename: M Z
authors.initials: MZ
authors.lastname: Hasan
authors.affiliation: Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
authors.forename: T
authors.initials: T
authors.lastname: Durakiewicz
authors.affiliation: School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332, USA.
authors.forename: Z
authors.initials: Z
authors.lastname: Jiang
authors.affiliation: Department of Physics, Purdue University, West Lafayette, Indiana 47907, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Department of Physics, Purdue University, West Lafayette, Indiana 47907, USA.
authors.forename: I
authors.initials: I
authors.lastname: Miotkowski
authors.affiliation: Department of Physics, Purdue University, West Lafayette, Indiana 47907, USA.
authors.forename: Y P
authors.initials: YP
authors.lastname: Chen
authors.affiliation: Department of Chemistry, Princeton University, Princeton, New Jersey 08544, USA.
authors.forename: S
authors.initials: S
authors.lastname: Jia
authors.affiliation: Department of Chemistry, Princeton University, Princeton, New Jersey 08544, USA.
authors.forename: H W
authors.initials: HW
authors.lastname: Ji
authors.affiliation: Department of Chemistry, Princeton University, Princeton, New Jersey 08544, USA.
authors.forename: R J
authors.initials: RJ
authors.lastname: Cava
authors.affiliation: Laboratoire de Physique des Solides, CNRS-UMR 8502, Université Paris-Sud, Orsay F-91405, France.
authors.forename: M
authors.initials: M
authors.lastname: Marsi