n-InSb的磁双光子带间吸收研究

通过测量光电导和调制光电导,观察到了15K温度下的n-InSb在CW CO_2激光照射产生的磁双光子吸收(TPMA).实验取Voigt位形,磁场沿111]晶向且最大为4.2T.实验的结果表明,“一次带内,一次带间”跃迁理论可以相当好地解释InSb中的TPMA过程,且大部分吸收为“球对称跃迁”,而其余为较弱的空间反演不对称、斜项和k_H跃迁.通过计算三阶非线性系数虚部得到的TPMA吸收系数与实验测得的双光子光电导之比较亦表明,现有的此方面的理论解释是成立的.

On the Two-Photon Magnetoabsorption in n-InSb

By measuring the photoconductivity (pc) and modulated pc,two-photon magnetoabsorption(TPMA) excited by CW CO_2 laser in n-InSb at T=15 K, in the Voigt configuration and mag-netic field in <111> orientation up to 4.2 T was observed.The experimental results show thatthe TPMA process in InSb could be explained adequately with the "interband-intraband"transition theory.Most of the absorptions observed are proved to be spherical transitions,while the remainders are induced from weaker inversion asymmetry transition,warping orK_H transitions.TPMA coefficients are derived by calculating the imaginary part of thethird nonlinear susceptibility.By comparing these coefficients with the changes in pc indu-ced by TPMA the current TPMA theory is confirmed.