title: Magnetic circular dichroism in two-photon photoemission.
abstract: We report the observation of magnetic circular dichroism (MCD) in two-photon photoemission (2PPE). The Heusler alloys Ni2MnGa and Co2FeSi were investigated by excitation with femtosecond laser light, showing MCD asymmetries of A=(3.5+/-0.5)x10;{-3} for Ni2MnGa and of A=(2.1+/-1.0)x10;{-3} for Co2FeSi, respectively. A theoretical explanation is provided based on local spin-density calculations for the magnetic dichroic response; the computed 2PPE MCD agrees well with the experiment. The observed 2PPE magnetic contrast represents an interesting alternative for future time-resolved photoemission studies on surface magnetism practicable in the laboratory.
authors.affiliation: Institut für Physik, Staudinger Weg 7, Universität Mainz, D-55128 Mainz, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Hild
authors.forename: J
authors.initials: J
authors.lastname: Maul
authors.forename: G
authors.initials: G
authors.lastname: Schönhense
authors.forename: H J
authors.initials: HJ
authors.lastname: Elmers
authors.forename: M
authors.initials: M
authors.lastname: Amft
authors.forename: P M
authors.initials: PM
authors.lastname: Oppeneer