Detection of Picosecond Magnetization Dynamics of 50 nm Magnetic Dots down to the Single Dot Regime

作者：Rana Bivas; Kumar Dheeraj; Barman Saswati; Pal Semanti; Fukuma Yasuhiro; Otani YoshiChika^*; Barman Anjan

来源：ACS Nano, 2011, 5(12): 9559-9565.

DOI：10.1021/nn202791g

• single nanomagnets dynamics
• time-resolved magneto-optical Kerr effect
• magnetization precession
• damping
• magnetostatic interaction

We report an all-optical time-domain detection of picosecond magnetization dynamics of arrays of 50 nm Ni80Fe20 (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.

• 出版日期2011-12