Magnetization reversal more rapidly by using an ultrashort square-wave laser pulse

TL;DR

This paper demonstrates that using an ultrashort square-wave laser pulse significantly accelerates magnetization reversal in a Co/Pt system compared to traditional Gaussian pulses, due to enhanced heat accumulation and the inverse Faraday effect.

Contribution

It introduces the use of a single ultrashort square-wave laser pulse for faster magnetization switching, highlighting the role of heat accumulation in the process.

Findings

Switching time is three times faster with SWLP than GWLP.

Threshold energy for all-optical switching is 0.67 mJ/cm2.

Heat accumulation significantly influences switching speed.

Abstract

With the feature of low-power magnetization manipulation at an ultrashort time scale, all optical switching (AOS) has been propelled to the forefront in investigations. To further speed up the magnetization reversal by manipulating ultrashort optical pulses, in this paper, one single square-wave laser pulse (SWLP) vie the combination of heating and Inverse Faraday Effect (IFE) is explored to excite the reversal of magnetization in a Co/Pt system. Simulation results show that the switching time of magnetization is 3 times faster than the using of a traditional Gaussian wave laser pulse (GWLP) under the same laser energy and pulse duration, and the threshold of AOS for the ferromagnet is 0.67 mJ/cm2. We furthermore demonstrate that the "heat accumulating effect" of laser-pulse is an important factor that influences the switching time, and a SWLP has a larger effect of heat accumulating than a GWLP.