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arXiv · 1305.5485

Infrared and Raman spectroscopy measurements of a transition in the crystal structure and a closing of the energy gap of BiTeI under pressure

M. K. Tran·J. Levallois·P. Lerch·J. Teyssier·A. B. Kuzmenko·G. Autès·O. V. Yazyev·A. Ubaldini·E. Giannini·D. van der Marel·A. Akrap
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Abstract

BiTeI is a giant Rashba spin splitting system, in which a non-centro symmetric topological phase has recently been suggested to appear under high pressure. We investigated the optical properties of this compound, reflectivity and transmission, under pressures up to $15$ GPa. The gap feature in the optical conductivity vanishes above $p \sim 9$ GPa and does not reappear up to at least $15$ GPa. The plasma edge, associated with intrinsically doped charge carriers, is smeared out through a phase transition at $9$ GPa. Using high pressure Raman spectroscopy, we follow the vibrational modes of BiTeI, providing additional clear evidence that the transition at 9 GPa involves a change of crystal structure. This change of crystal structure possibly inhibits the high-pressure topological phase from occurring.

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M. K. Tran, J. Levallois, P. Lerch, J. Teyssier, A. B. Kuzmenko, G. Autès, O. V. Yazyev, A. Ubaldini, E. Giannini, D. van der Marel, A. Akrap. 2013-12-19. Infrared and Raman spectroscopy measurements of a transition in the crystal structure and a closing of the energy gap of BiTeI under pressure. https://doi.org/10.1103/physrevlett.112.047402

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