Abstract
We here report a detailed high-pressure infrared transmission study of BiTeCl and BiTeBr. We follow the evolution of two band transitions: the optical excitation between two Rashba-split conduction bands, and the absorption across the band gap. In the low-pressure range, GPa, for both compounds is approximately constant with pressure and decreases, in agreement with band structure calculations. In BiTeCl, a clear pressure-induced phase transition at 6 GPa leads to a different ground state. For BiTeBr, the pressure evolution is more subtle, and we discuss the possibility of closing and reopening of the band gap. Our data is consistent with a potential Weyl phase in BiTeBr at GPa, followed by the onset of a structural phase transition above 7 GPa.
- Received 12 October 2016
DOI:https://doi.org/10.1103/PhysRevB.95.045201
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