光诱导反铁磁性绝缘体Cr_2O_3超快退磁动力学研究

Research on Photoinduced Ultrafast Demagnetization Dynamics in an Antiferromagnetic Insulator Cr_2O_3

研究了光激发反铁磁性绝缘体Cr_2O_3超快退磁动力学.通过对反铁磁性Cr_2O_3的光吸收谱进行分析,计算了不同态之间的能量差.通过解耗散薛定谔方程研究了2.5 e V激发电子从高自旋态到低自旋态的超快动力学过程.利用数值模拟的方法计算出反铁磁性绝缘体Cr_2O_3的退磁时间为350飞秒,这个结果与实验结果符合得很好;此外,进一步分析了Cr_2O_3的退磁路径.证明耗散薛定谔方程是研究电子从高自旋态到低自旋态弛豫的一种有效的量子方法.

In this paper,the photoexcited ultrafast demagnetization dynamics in an antiferromagnetic insulator Cr_2O_3 is studied.The energy gaps between different states are calculated by analyzing the optical absorption spectra of the antiferromagnetic Cr_2O_3.The dissipative Schrodinger equation is applied to study the ultrafast dynamical evolution process of the electrons from high spin states to low spin states after the energy 2.5 e V excitation.In the antiferromagnetic insulator,the demagnetization time was around 350 femtoseconds according to the numerical simulation,which agrees well with the experimentally observed results.We further analyze the demagnetization path of Cr_2O_3.This paper demonstrate that the dissipative schr dinger equation is an effective quantum method to study electron relaxation from a high spin state to a low spin state.