Detection of picosecond magnetization dynamics of 50 nm magnetic dots down to the single dot regime.
We report an all-optical time-domain detection of picosecond magnetization dynamics of arrays of 50 nm Ni(80)Fe(20) (permalloy) dots down to the single nanodot regime. In the single nanodot regime the dynamics reveals one dominant resonant mode corresponding to the edge mode of the 50 nm dot with slightly higher damping than that of the unpatterned thin film. With the increase in areal density of the array both the precession frequency and damping increase significantly due to the increase in magnetostatic interactions between the nanodots, and a mode splitting and sudden jump in apparent damping are observed at an edge-to-edge separation of 50 nm.
Department of Condensed Matter Physics and Material Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata 700 098, India.
Bivas
B
Rana
Dheeraj
D
Kumar
Saswati
S
Barman
Semanti
S
Pal
Yasuhiro
Y
Fukuma
YoshiChika
Y
Otani
Anjan
A
Barman
D004867:Equipment Design; D019544:Equipment Failure Analysis; D008280:Magnetics / Q000295:instrumentation*; D008422:Materials Testing / Q000379:methods*; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size