Theoretical Investigation of All Optical Switching by Intersystem Crossing

Yuhao Zou,Haozhe Huang,Zhihao Zeng,Changsheng Xie,Xiangping Li,Kai Wang,Sicong Wang,Haiwei Wang

doi:10.3390/app10010128

Abstract

The dynamics of spin flips induced by the femtosecond laser are theoretically investigated in this article. The spin flips in this scenario are attributed to the intersystem crossing (ISC) described within the frame of the Rabi model. This new explanation is a step attempting to explain the mechanism of the all-optical magnetic orientation switching in the perspective of the conservation of the angular momentum and breaks of the selection rule, which is ignored in the Raman scattering related explanations. The final spin states discussed herein are closely related to the intensity of the incident laser and the ISC decay rate. The quantitative analysis of the relation between decay rate, temperature and the intensity of the laser is discussed.

Highlights

Occurring on numerous ferri [1,2,3,4,5,6] and ferromagnetic [7,8,9,10] materials, all-optical switching (AOS) is considered as a universal phenomenon
The model of the electron transition coupling with the spin flip is presented to explain the process of AOS
The dynamic of the spin flip is described on the base of Rabi model, and the main cause for AOS is attributed to intersystem crossing (ISC)

Summary

Introduction

Occurring on numerous ferri [1,2,3,4,5,6] and ferromagnetic [7,8,9,10] materials, all-optical switching (AOS) is considered as a universal phenomenon. Taking the ultrafast heating as a dominant factor, the two-temperature model works well in the magnetic orientation reversal of anti-ferromagnetic coupled materials [14,15]. It fails to explain the transient ferromagnetic state in which the magnetic orientation of the transient metal sublattice reverses and gets parallel to that of the rare earth after demagnetization of the transient metal sublattice

Results

Discussion

Conclusion