Title :
Excitation of coherent spin waves at ultrafast thermomagnetic writing
Author :
Tsukamoto, A. ; Nakagawa, K. ; Itoh, A. ; Kimel, A. ; Tsvetkov, A. ; Awano, H. ; Ohta, N. ; Kirilyuk, A. ; Rasing, Th.
Author_Institution :
Coll. of Sci. & Technol., Nihon Univ., Chiba, Japan
fDate :
7/1/2004 12:00:00 AM
Abstract :
We present results of a time-resolved study of the ultrafast magnetic response of Gd23.1Fe71.9Co5.0 magnetically amplified magnetooptical systems (MAMMOS) structures under conditions near actual read/write temperatures. An all-optical pump and probe method was used in which an intense (pump) light beam excited a medium due to ultrafast laser heating and a less intense (probe) beam monitored this photo-excited state through the magnetooptical Kerr effect. Our experiment clearly demonstrates that the photo-excitation effectively excites coherent spin waves in the magnetic material. Precession frequencies of several gigahertz and relaxation times in the nanosecond range were observed.
Keywords :
Kerr magneto-optical effect; cobalt alloys; gadolinium alloys; iron alloys; magnetisation; magneto-optical devices; optical pumping; spin waves; thermomagnetic recording; Gd23.1Fe71.9Co5.0; MAMMOS; all-optical pump; coherent spin wave excitation; light beam excitation; magnetic material; magnetically amplified magnetooptical systems; magnetization precession; magnetooptical Kerr effect; optical probe; photo-excitation; photo-excited state; read temperature; relaxation times; ultrafast laser heating; ultrafast magnetic response; ultrafast thermomagnetic writing; write temperature; Heat pumps; Iron; Kerr effect; Laser beams; Laser excitation; Magnetooptic effects; Probes; Pump lasers; Temperature; Writing; MAMMOS; Magnetization precession; thermo-magnetic writing;
Journal_Title :
Magnetics, IEEE Transactions on
DOI :
10.1109/TMAG.2004.834201
