自旋-轨道耦合对磁性绝缘体磁光Kerr效应的影响

采用单原子能级跃迁模型,导出在同时考虑自旋交换劈裂和自旋轨道耦合时磁光Kerr旋转的微观表达式,并就四能级跃迁情况,研究了磁光效应随原子基态及激发态能级自旋轨道耦合常数的变化规律.结果表明:磁光Kerr旋转角与自旋轨道耦合劈裂能量不成正比;单原子能级自旋轨道耦合常数为正或中间激发态自旋轨道耦合常数为负时,有利于提高磁光Kerr旋转. 关键词： 磁光Kerr效应 自旋轨道耦合 线性响应核 劈裂

Influence of spin-orbit coupling on magneto-optical Kerr effect of a magnetic insulator

By using atomic energy level transition model for local electrons, microscopic quantum expressions of the magneto optical Kerr rotation (MOKR) are derived, taking into account both spin exchange splitting and spin orbit coupling interaction. Variation of the MOKR with the coupling constants of atomic ground state or excited states is investigated for the four level transition case. Results show that MOKR is not proportional to the spin orbit coupling splitting energy. It is advantageous to the enhancement of MOKR when the spin orbit coupling constant of the atomic ground states is positive or that of the excited states is negative.