外磁场对(Ga,Mn)As有效g因子的影响

Effects of external magnetic field on the effective g factor of (Ga,Mn) As

利用时间分辨Kerr旋光技术测量低温下稀磁半导体Ga0.937Mn0.063As中光注入极化载流子的自旋进动信号,并观察到自旋极化载流子的有效g因子值随外磁场的增强而增大的反常现象.这归结于磁场导致局域化空穴转化为非局域化空穴,从而使自发磁化强度增强,有效g因子值增大.基于此物理图像,进一步给出了(Ga,Mn)As的有效g因子与外磁场的关系式.

With the help of time resolved magneto-optic Kerr rotation measurements,the optically induced spin precession in heavily doped diluted magnetic semiconductor Ga0.937Mn0.063As was observed.It was found that the effective g factor increases with increasing magnetic field,which is attributed to the magnetic-field-induced increase of the density of the non-localized holes.Those free holes will couple with the localized magnetic ions by p-d interactions,leading to the formation of spontaneous magnetization in Ga0.937Mn0.063As,which in turn to the enhancement of the effective g factor.