Infrared absorption, multiphonon processes and time reversal effect on Si and Ge band structure

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Article

Kunert, H. W.¹  Machatine, A. G. J.¹  Malherbe, J. B.¹  Barnas, J.²  Hoffmann, A.³  Wagner, M. R.³ 

[1] Univ Pretoria, Dept Phys, ZA-0002 Pretoria, South Africa

[2] Adam Mickiewicz Univ Poznan, Dept Phys, PL-61614 Poznan, Poland

[3] Tech Univ Berlin, Inst Festkorperphys, D-10623 Berlin, Germany

关键词: Infrared absorption;    Time reversal;    Phonons;    Space groups;    Selection rules;    Si;    Ge;   

DOI  :  10.1016/j.tsf.2008.08.033

来源: Elsevier

【 摘 要 】

We have examined the effect of Time Reversal Symmetry (TRS) on vibrational modes and on the electronic band structure of Si and Ge. Most of the primary non-interacting modes are not affected by TRS. Only phonons originating from high symmetry lines 5 and A of the Brillouin Zone (BZ) indicate extra degeneracy. Selection rules for some two and three phonons originating from high symmetry lines are determined. The states of electrons and holes described by electronic band structure due to spin-inclusion are assigned by spinor representations of the double space group. Inclusion of the TRS into the band structure results in extra degeneracy of electrons and holes, and therefore optical selection rules suppose to be modified. (C) 2008 Elsevier B.V. All rights reserved.

【 授权许可】

Free