title: All-optical manipulation and probing of the d-f exchange interaction in EuTe.
abstract: We demonstrate that the ultrafast fast dynamics of the d-f exchange interaction, between conduction band electrons and lattice spins in EuTe, can be accessed using an all-optical technique. Our results reveal, in full detail, the time evolution of the d-f exchange interaction induced by a femtosecond laser pulse. Specifically, by monitoring the time resolved dynamics of the reflectivity changes and Kerr rotation of a weak light pulse reflected from the surface of the sample, it is shown that an intense femtosecond light pulse with photon energies higher than that of the bandgap, triggers spin waves in EuTe. The laser-induced spin waves modulate the d-f exchange interaction, and cause the bandgap to oscillate with an amplitude reaching 1 meV, at frequencies up to tens of GHz. The ability to control and monitor the dynamics of the exchange energy with our all-optical technique opens up new opportunities for the manipulation of magnetism at ultrafast time-scales.
authors.affiliation: Radboud University Nijmegen, Institute for Molecules and Materials, 6525 AJ, Nijmegen, The Netherlands.
authors.forename: R R
authors.initials: RR
authors.lastname: Subkhangulov
authors.affiliation: Instituto de Fisica, Universidade de Sao Paulo, Caixa Postal 66318, CEP 05315-970 Sao Paulo, Brazil.
authors.forename: A B
authors.initials: AB
authors.lastname: Henriques
authors.affiliation: LAS-INPE, 12227-010 Sao Jose dos Campos, Brazil.
authors.forename: P H O
authors.initials: PH
authors.lastname: Rappl
authors.affiliation: LAS-INPE, 12227-010 Sao Jose dos Campos, Brazil.
authors.forename: E
authors.initials: E
authors.lastname: Abramof
authors.affiliation: Radboud University Nijmegen, Institute for Molecules and Materials, 6525 AJ, Nijmegen, The Netherlands.
authors.forename: Th
authors.initials: T
authors.lastname: Rasing
authors.affiliation: Radboud University Nijmegen, Institute for Molecules and Materials, 6525 AJ, Nijmegen, The Netherlands.
authors.forename: A V
authors.initials: AV
authors.lastname: Kimel
mesh_terms: D004583:Electrons; D005063:Europium / Q000737:chemistry*; D053844:Lasers, Solid-State; D008280:Magnetics / Q000295:instrumentation*; D055096:Optical Devices; D017785:Photons; D011789:Quantum Theory; D013691:Tellurium / Q000737:chemistry*; D013997:Time Factors
chemical_list: D005063:Europium; D013691:Tellurium