What has been measured by reflection magnetic circular dichroism in Ga sub(1-x)Mn sub(x)As/GaAs structures?

• Published in: Chinese physics B 2014-07, Vol.23 (7), p.077801-1-077801-7
• Main Authors: He, Zhen-Xin, Zheng, Hou-Zhi, Huang, Xue-Jiao, Wang, Hai-Long, Zhao, Jian-Hua
• Format: Article
• Language: English
• Subjects: Circularity; Dichroism; Dielectrics; Gallium arsenides; Interference; Mathematical analysis; Reflection; Tensors
• ISSN: 1674-1056; 1741-4199
• DOI: 10.1088/1674-1056/23/7/077801

(ProQuest: ... denotes formulae and/or non-USASCII text omitted) An explicit expression of reflection magnetic circular dichroism (R sub(MCD)) has been derived, taking into account the interference effect that arises from multiple internal reflections in an air/Ga sub(1-x)Mn sub(x)As/GaAs dielectric layered system. It unambiguously shows that the R sub(MCD) signal is composed by three terms. In addition to the conventional term, which is sufficient in the absence of interference, an oscillatory term is required. Both of them are related to the imaginary part ... of the off-diagonal element of the dielectric tensor. One also becomes aware that in this case R sub(MCD) is not actually determined only by the imaginary part ... of the off-diagonal element of the dielectric tensor, as has been widely accepted. In fact, the real part ... of the off-diagonal element will substantially mix into the measured R sub(MCD) results by another oscillatory cos [straighttheta] form. It can even reverse the sign of R sub(MCD), when the Ga sub(1-x)Mn sub(x)As layer becomes thicker. The main aspects of these predictions were used to reasonably explain the R sub(MCD) results measured in three different types of samples. Our work will bring about a reconsideration of how to correctly explain R sub(MCD) results.