title: Attosecond nonlinear polarization and light-matter energy transfer in solids.
abstract: Electric-field-induced charge separation (polarization) is the most fundamental manifestation of the interaction of light with matter and a phenomenon of great technological relevance. Nonlinear optical polarization produces coherent radiation in spectral ranges inaccessible by lasers and constitutes the key to ultimate-speed signal manipulation. Terahertz techniques have provided experimental access to this important observable up to frequencies of several terahertz. Here we demonstrate that attosecond metrology extends the resolution to petahertz frequencies of visible light. Attosecond polarization spectroscopy allows measurement of the response of the electronic system of silica to strong (more than one volt per ångström) few-cycle optical (about 750 nanometres) fields. Our proof-of-concept study provides time-resolved insight into the attosecond nonlinear polarization and the light-matter energy transfer dynamics behind the optical Kerr effect and multi-photon absorption. Timing the nonlinear polarization relative to the driving laser electric field with sub-30-attosecond accuracy yields direct quantitative access to both the reversible and irreversible energy exchange between visible-infrared light and electrons. Quantitative determination of dissipation within a signal manipulation cycle of only a few femtoseconds duration (by measurement and ab initio calculation) reveals the feasibility of dielectric optical switching at clock rates above 100 terahertz. The observed sub-femtosecond rise of energy transfer from the field to the material (for a peak electric field strength exceeding 2.5 volts per ångström) in turn indicates the viability of petahertz-bandwidth metrology with a solid-state device.
authors.affiliation: Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Strasse 1, 85748 Garching, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Sommer
authors.affiliation: Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Strasse 1, 85748 Garching, Germany.|Fakultät für Physik, Ludwig-Maximilians-Universität, Am Coulombwall 1, 85748 Garching, Germany.
authors.forename: E M
authors.initials: EM
authors.lastname: Bothschafter
authors.affiliation: Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba 305-8571, Japan.
authors.forename: S A
authors.initials: SA
authors.lastname: Sato
authors.affiliation: Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Strasse 1, 85748 Garching, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Jakubeit
authors.affiliation: Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Strasse 1, 85748 Garching, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Latka
authors.affiliation: Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Strasse 1, 85748 Garching, Germany.
authors.forename: O
authors.initials: O
authors.lastname: Razskazovskaya
authors.affiliation: Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Strasse 1, 85748 Garching, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Fattahi
authors.affiliation: Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Strasse 1, 85748 Garching, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Jobst
authors.affiliation: Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Strasse 1, 85748 Garching, Germany.|Fakultät für Physik, Ludwig-Maximilians-Universität, Am Coulombwall 1, 85748 Garching, Germany.
authors.forename: W
authors.initials: W
authors.lastname: Schweinberger
authors.affiliation: Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Strasse 1, 85748 Garching, Germany.
authors.forename: V
authors.initials: V
authors.lastname: Shirvanyan
authors.affiliation: Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Strasse 1, 85748 Garching, Germany.|Center for Nano-Optics and Department of Physics and Astronomy, Georgia State University, Atlanta, Georgia 30303, USA.
authors.forename: V S
authors.initials: VS
authors.lastname: Yakovlev
authors.affiliation: Physik-Department, Technische Universität München, James-Franck-Strasse 1, 85748 Garching, Germany.
authors.forename: R
authors.initials: R
authors.lastname: Kienberger
authors.affiliation: Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba 305-8571, Japan.|Center for Computational Sciences, University of Tsukuba, Tsukuba 305-8577, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Yabana
authors.affiliation: Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Strasse 1, 85748 Garching, Germany.
authors.forename: N
authors.initials: N
authors.lastname: Karpowicz
authors.affiliation: Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Strasse 1, 85748 Garching, Germany.|Fakultät für Physik, Ludwig-Maximilians-Universität, Am Coulombwall 1, 85748 Garching, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Schultze
authors.affiliation: Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Strasse 1, 85748 Garching, Germany.|Fakultät für Physik, Ludwig-Maximilians-Universität, Am Coulombwall 1, 85748 Garching, Germany.
authors.forename: F
authors.initials: F
authors.lastname: Krausz