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arXiv · 1605.09764

The role of electron and phonon temperatures in the helicity-independent all-optical switching of GdFeCo

Jon Gorchon·Richard B. Wilson·Yang Yang·Akshay Pattabi·Junyang Chen·Li He·Jianping Wang·Mo Li·Jeffrey Bokor
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Abstract

Ultrafast optical heating of the electrons in ferrimagnetic metals can result in all-optical switching (AOS) of the magnetization. Here we report quantitative measurements of the temperature rise of GdFeCo thin films during helicity-independent AOS. Critical switching fluences are obtained as a function of the initial temperature of the sample and for laser pulse durations from 55 fs to 15 ps. We conclude that non-equilibrium phenomena are necessary for helicity-independent AOS, although the peak electron temperature does not play a critical role. Pump-probe time-resolved experiments show that the switching time increases as the pulse duration increases, with 10 ps pulses resulting in switching times of ~sim 13 ps. These results raise new questions about the fundamental mechanism of helicity-independent AOS.

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Jon Gorchon, Richard B. Wilson, Yang Yang, Akshay Pattabi, Junyang Chen, Li He, Jianping Wang, Mo Li, Jeffrey Bokor. 2016-05-31. The role of electron and phonon temperatures in the helicity-independent all-optical switching of GdFeCo. https://doi.org/10.1103/physrevb.94.184406

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