title: Coherent optical phonons and parametrically coupled magnons induced by femtosecond laser excitation of the Gd(0001) surface.
abstract: Coherent spin dynamics in the THz domain coupled to a coherent phonon is observed in the time-resolved second harmonic response of the Gd(0001) ferromagnetic metal surface. An LO phonon of 2.9 THz is excited by a transient charge displacement at the surface caused by resonant absorption of a fs laser pulse in the exchange-split surface state. This lattice vibration modulates the interlayer distance inducing a coherent variation of the exchange interaction between spins in adjacent layers. The resulting magnetization dynamics is considered as optical magnon wave packets coupled to the phonon.
authors.affiliation: Freie Universität Berlin, Fachbereich Physik, Arnimallee 14, 14195 Berlin-Dahlem, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Melnikov
authors.forename: I
authors.initials: I
authors.lastname: Radu
authors.forename: U
authors.initials: U
authors.lastname: Bovensiepen
authors.forename: O
authors.initials: O
authors.lastname: Krupin
authors.forename: K
authors.initials: K
authors.lastname: Starke
authors.forename: E
authors.initials: E
authors.lastname: Matthias
authors.forename: M
authors.initials: M
authors.lastname: Wolf