title: Carrier-wave Rabi-flopping signatures in high-order harmonic generation for alkali atoms.
abstract: We present a theoretical investigation of carrier-wave Rabi flopping in real atoms by employing numerical simulations of high-order harmonic generation (HHG) in alkali species. Given the short HHG cutoff, related to the low saturation intensity, we concentrate on the features of the third harmonic of sodium (Na) and potassium (K) atoms. For pulse areas of 2π and Na atoms, a characteristic unique peak appears, which, after analyzing the ground state population, we correlate with the conventional Rabi flopping. On the other hand, for larger pulse areas, carrier-wave Rabi flopping occurs, and is associated with a more complex structure in the third harmonic. These characteristics observed in K atoms indicate the breakdown of the area theorem, as was already demonstrated under similar circumstances in narrow band gap semiconductors.
authors.affiliation: Max-Planck Institut für Quantenoptik, Hans-Kopfermann-Strasse 1, D-85748 Garching, Germany.
authors.forename: M F
authors.initials: MF
authors.lastname: Ciappina
authors.affiliation: Centro de Láseres Pulsados (CLPU), Parque Científico, E-37008 Villamayor, Salamanca, Spain.
authors.forename: J A
authors.initials: JA
authors.lastname: Pérez-Hernández
authors.affiliation: Max-Planck Institut für Physik komplexer Systeme, Nöthnitzer Strasse 38, D-01187 Dresden, Germany.
authors.forename: A S
authors.initials: AS
authors.lastname: Landsman
authors.affiliation: Physics Department, ETH Zurich, CH-8093 Zurich, Switzerland.
authors.forename: T
authors.initials: T
authors.lastname: Zimmermann
authors.affiliation: ICFO-Institut de Ciènces Fotòniques, Mediterranean Technology Park, 08860 Castelldefels (Barcelona), Spain.|ICREA-Institució Catalana de Recerca i Estudis Avançats, Lluis Companys 23, 08010 Barcelona, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Lewenstein
authors.affiliation: Centro de Láseres Pulsados (CLPU), Parque Científico, E-37008 Villamayor, Salamanca, Spain.
authors.forename: L
authors.initials: L
authors.lastname: Roso
authors.affiliation: Max-Planck Institut für Quantenoptik, Hans-Kopfermann-Strasse 1, D-85748 Garching, Germany.|Department für Physik, Ludwig-Maximilians-Universität München, Am Coulombwall 1, D-85748 Garching, Germany.
authors.forename: F
authors.initials: F
authors.lastname: Krausz