Ultrafast generation of ferromagnetic order via a laser-induced phase transformation in FeRh thin films.
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.
Ju
Ganping
G
Seagate Research, 1251 Waterfront Place, Pittsburgh, Pennsylvania 15222, USA. Ganping.Ju@Seagate.com
Hohlfeld
Julius
J
Bergman
Bastiaan
B
van de Veerdonk
René J M
RJ
Mryasov
Oleg N
ON
Kim
Jai-Young
JY
Wu
Xiaowei
X
Weller
Dieter
D
Koopmans
Bert
B