title: Ultrafast generation of ferromagnetic order via a laser-induced phase transformation in FeRh thin films.
abstract: It is demonstrated that ultrafast generation of ferromagnetic order can be achieved by driving a material from an antiferromagnetic to a ferromagnetic state using femtosecond optical pulses. Experimental proof is provided for chemically ordered FeRh thin films. A subpicosecond onset of induced ferromagnetism is followed by a slower increase over a period of about 30 ps when FeRh is excited above a threshold fluence. Both experiment and theory provide evidence that the underlying phase transformation is accompanied, but not driven, by a lattice expansion. The mechanism for the observed ultrafast magnetic transformation is identified to be the strong ferromagnetic exchange mediated via Rh moments induced by Fe spin fluctuations.
authors.affiliation: Seagate Research, 1251 Waterfront Place, Pittsburgh, Pennsylvania 15222, USA. Ganping.Ju@Seagate.com
authors.forename: Ganping
authors.initials: G
authors.lastname: Ju
authors.forename: Julius
authors.initials: J
authors.lastname: Hohlfeld
authors.forename: Bastiaan
authors.initials: B
authors.lastname: Bergman
authors.forename: René J M
authors.initials: RJ
authors.lastname: van de Veerdonk
authors.forename: Oleg N
authors.initials: ON
authors.lastname: Mryasov
authors.forename: Jai-Young
authors.initials: JY
authors.lastname: Kim
authors.forename: Xiaowei
authors.initials: X
authors.lastname: Wu
authors.forename: Dieter
authors.initials: D
authors.lastname: Weller
authors.forename: Bert
authors.initials: B
authors.lastname: Koopmans