Elastic and Magnetic Dynamics of Nanomagnet-Ordered Arrays Impulsively Excited by Subpicosecond Laser Pulses

作     者：A. Comin C. Giannetti G. Samoggia P. Vavassori D. Grando P. Colombi E. Bontempi L. E. Depero V. Metlushko B. Ilic F. Parmigiani 

作者机构：Sincrotrone Trieste I-34012 Basovizza Trieste Italy and Dipartimento di Matematica e Fisica Università Cattolica del Sacro Cuore I-25121 Brescia Italy Dipartimento di Fisica “A. Volta” Università degli Studi di Pavia I-27100 Pavia Italy CNR-INFM CRS S3 and Dipartimento di Fisica Università di Ferrara I-44100 Ferrara Italy Dipartimento di Elettronica Università degli Studi di Pavia I-27100 Pavia Italy Laboratorio di Chimica per le Tecnologie Università degli Studi di Brescia I-25123 Brescia Italy Department of Electrical and Computer Engineering University of Illinois at Chicago Chicago Illinois 60607 USA Cornell Nanofabrication Facility School of Applied and Engineering Physics Cornell University Ithaca New York 14853 USA Dipartimento di Fisica Università degli Studi di Trieste I-34127 Trieste Italy and Sincrotrone Trieste I-34012 Basovizza Trieste Italy 

出 版 物：《Physical Review Letters》 (Phys Rev Lett)

年 卷 期：2006年第97卷第21期

页      面：217201-217201页

核心收录：

学科分类：07[理学] 0702[理学-物理学] 

主　　题：Nanostructured materials 

摘      要：This Letter reports on the first observation of elastic and magnetic dynamics of ordered arrays of permalloy nanodots excited by low-intensity 120 fs light pulses. The first order of the diffraction pattern, generated by the probe beam in a pump-probe configuration, is used for time-resolved reflectivity and time-resolved magneto-optical Kerr effect measurements. The nonadiabatical absorption of the pump triggers an acoustic standing wave, detected by the reflected probe signal, with a frequency related to the array wave vector. Instead, the magneto-optical signal exhibits, on the nanosecond time scale, the signature of the heat-exchange diffusion processes. In addition, a clear oscillation of the magnetic signal, at a frequency close to the frequency of the acoustic wave, is unambiguously detected. Finally, the interplay between the elastic and magnetic dynamics is analyzed and interpreted.