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Proceedings Paper

Ultrafast dynamics of Au/TmIG and Au/YIG bilayers in response to picosecond heating (Conference Presentation)
Author(s): Richard Wilson; Michael Gomez; Yawen Liu; Jing Shi

Paper Abstract

Ultrafast control of magnetic order in materials requires a fundamental understanding of how energy and angular momentum flow between electronic, magnetic, and vibrational degrees-of-freedom. We investigate the ultrafast response of Au/TmIG and Au/YIG bilayers to ultrafast laser heating of the Au electrons. In the picoseconds after heating, large interfacial spin currents occur due to a temperature imbalance between electrons and phonons in the metal, and magnons and phonons in the magnetic insulator. We utilize four different optical probes to develop a complete picture of the heat and spin transport in Au/TmIG and Au/YIG. Magneto-optic Kerr effect measurements of Au at a wavelength of 800 nm detects the spin accumulation in the normal metal that results from interfacial spin-currents. Magneto-optic Kerr effect measurements at 400 nm monitor the ultrafast magnetization dynamics of the garnet insulator that occur due to increases in magnon population. Finally, thermoreflectance measurements at 690 and 950 nm monitor the temperature evolution of the Au electrons and phonons, respectively. Together, these measurements allow us to estimate the magnitude of the transport coefficients responsible for the longitudinal spin-Seebeck effect in these systems. These coefficients include the electron-magnon conductance of the Au/TmIG and Au/YIG interfaces, the electron-phonon coupling in the Au layer, and the magnon-phonon coupling in the TmIG and YIG layers.

Paper Details

Date Published: 18 September 2018
Proc. SPIE 10732, Spintronics XI, 107322U (18 September 2018); doi: 10.1117/12.2321986
Show Author Affiliations
Richard Wilson, Univ. of California, Riverside (United States)
Michael Gomez, Univ. of California, Riverside (United States)
Yawen Liu, Univ. of California, Riverside (United States)
Jing Shi, Univ. of California, Riverside (United States)

Published in SPIE Proceedings Vol. 10732:
Spintronics XI
Henri-Jean Drouhin; Jean-Eric Wegrowe; Manijeh Razeghi; Henri Jaffrès, Editor(s)

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