北京大学学报(自然科学版)

稀磁半导体Cd1-xMnxTe,Cd1-xFexTe的巨法拉第效应

王荣明,王学忠,陈辰嘉   

  1. 北京大学物理学系,北京,100871
  • 收稿日期:1994-09-07 出版日期:1995-09-20 发布日期:1995-09-20

Giant Faraday Rotation in Diluted Magnetic Semiconductors Cd1-xMnxTe and Cd1-xFexTe

WANG Rongming, WANG Xuezhong, CHEN Chenjia   

  1. Department of Physics, Peking University, Beijing, 100871
  • Received:1994-09-07 Online:1995-09-20 Published:1995-09-20

摘要: 用消光法、交替磁场法和磁光调制法测量了不同温度下、不同组分的稀磁半导体Cd1-xMnxTe和Cd1-xFexTe的巨法拉第效应。实验表明:对较高组分的Cd1-xMnxTe(x ≥0.1),法拉第旋转角为负,用单振子模型能很好地描述实验结果。稀磁半导体Cd1-xFexTe表现出与Cd1-xMnxTe同量级的巨法拉第效应,当组分较低时,法拉第旋转角随入射光子能量出现由正到负的变化,必须用多振子模型才能很好解释实验结果。当样品很薄或磁场较低时,磁光调制法以其很高的测量精度显示出巨大的优越性。

关键词: 稀磁半导体, 法拉第效应, 磁光调制

Abstract: Giant Faraday rotation as a function of photon energy andcomposition for Cd1-xMnxTe and Cd1-xFexTe in temperature range 70K to 300K has been measured by using extinction, alternating magnetic field and magneto-optical modulation methods. Faraday rotation angles are negative and a single-oscillator model fit the data very well for Cd1-xMnxTe with relatively high compositions (x ≥0.1). It is shown that Cd1-xFexTe crystals exhibit the same order giant Faraday rotation cha-racteristic as Cd1-xMnxTe. With relatively low composition x, Faraday rotation angles vary from positive to negative when photon energy closeto the band gap edge, a multioscillator model has been successfully usedto explain the data. Alternating magnetic field method is found to be the best one in this region, however, magneto-optical modulation methodtakes advantages of its high accurate for thin samples or under low magnetic field.

Key words: diluted magnetic semiconductors, faraday effect, magneto-optical-modulation

中图分类号: