title: Self-amplified photo-induced gap quenching in a correlated electron material.
abstract: Capturing the dynamic electronic band structure of a correlated material presents a powerful capability for uncovering the complex couplings between the electronic and structural degrees of freedom. When combined with ultrafast laser excitation, new phases of matter can result, since far-from-equilibrium excited states are instantaneously populated. Here, we elucidate a general relation between ultrafast non-equilibrium electron dynamics and the size of the characteristic energy gap in a correlated electron material. We show that carrier multiplication via impact ionization can be one of the most important processes in a gapped material, and that the speed of carrier multiplication critically depends on the size of the energy gap. In the case of the charge-density wave material 1T-TiSe2, our data indicate that carrier multiplication and gap dynamics mutually amplify each other, which explains-on a microscopic level-the extremely fast response of this material to ultrafast optical excitation.
authors.affiliation: I. Physikalisches Institut, Georg-August-Universität Göttingen, 37077 Göttingen, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Mathias
authors.affiliation: Department of Physics and Research Center OPTIMAS, University of Kaiserslautern, 67663 Kaiserslautern, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Eich
authors.affiliation: Department of Physics and Research Center OPTIMAS, University of Kaiserslautern, 67663 Kaiserslautern, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Urbancic
authors.affiliation: Department of Physics and Research Center OPTIMAS, University of Kaiserslautern, 67663 Kaiserslautern, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Michael
authors.affiliation: JILA, University of Colorado and NIST, Boulder, Colorado 80309-0440, USA.
authors.forename: A V
authors.initials: AV
authors.lastname: Carr
authors.affiliation: Department of Physics and Research Center OPTIMAS, University of Kaiserslautern, 67663 Kaiserslautern, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Emmerich
authors.affiliation: Institute of Experimental and Applied Physics, University of Kiel, 24098 Kiel, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Stange
authors.affiliation: JILA, University of Colorado and NIST, Boulder, Colorado 80309-0440, USA.
authors.forename: T
authors.identifier: 0000-0002-2023-2226
authors.initials: T
authors.lastname: Popmintchev
authors.affiliation: Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.|Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors.forename: T
authors.initials: T
authors.lastname: Rohwer
authors.affiliation: Department of Physics and Research Center OPTIMAS, University of Kaiserslautern, 67663 Kaiserslautern, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Wiesenmayer
authors.affiliation: Department of Physics and Research Center OPTIMAS, University of Kaiserslautern, 67663 Kaiserslautern, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Ruffing
authors.affiliation: Department of Physics and Research Center OPTIMAS, University of Kaiserslautern, 67663 Kaiserslautern, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Jakobs
authors.affiliation: Institute of Experimental and Applied Physics, University of Kiel, 24098 Kiel, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Hellmann
authors.affiliation: JILA, University of Colorado and NIST, Boulder, Colorado 80309-0440, USA.
authors.forename: P
authors.initials: P
authors.lastname: Matyba
authors.affiliation: JILA, University of Colorado and NIST, Boulder, Colorado 80309-0440, USA.
authors.forename: C
authors.initials: C
authors.lastname: Chen
authors.affiliation: Institute of Experimental and Applied Physics, University of Kiel, 24098 Kiel, Germany.
authors.forename: L
authors.initials: L
authors.lastname: Kipp
authors.affiliation: Institute of Experimental and Applied Physics, University of Kiel, 24098 Kiel, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Bauer
authors.affiliation: JILA, University of Colorado and NIST, Boulder, Colorado 80309-0440, USA.
authors.forename: H C
authors.initials: HC
authors.lastname: Kapteyn
authors.affiliation: Department of Physics and Research Center OPTIMAS, University of Kaiserslautern, 67663 Kaiserslautern, Germany.
authors.forename: H C
authors.initials: HC
authors.lastname: Schneider
authors.affiliation: Institute of Experimental and Applied Physics, University of Kiel, 24098 Kiel, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Rossnagel
authors.affiliation: JILA, University of Colorado and NIST, Boulder, Colorado 80309-0440, USA.
authors.forename: M M
authors.initials: MM
authors.lastname: Murnane
authors.affiliation: Department of Physics and Research Center OPTIMAS, University of Kaiserslautern, 67663 Kaiserslautern, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Aeschlimann