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arXiv · 2311.08312

Exchange gap in GdPtBi probed by magneto-optics

S. Polatkan·E. Uykur·I. Mohelsky·J. Wyzula·M. Orlita·C. Shekhar·C. Felser·M. Dressel·A. V. Pronin
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Abstract

We measured the magneto-reflectivity spectra (4 - 90 meV, 0 - 16 T) of the triple-point semimetal GdPtBi and found them to demonstrate two unusual broad features emerging in field. The electronic bands of GdPtBi are expected to experience large exchange-mediated shifts, which lends itself to a description via effective Zeeman splittings with a large g factor. Based on this approach, along with an ab initio band structure analysis, we propose a model Hamiltonian that describes our observations well and allows us to estimate the effective g factor, g* = 95. We conclude that we directly observe the exchange-induced $\Gamma_{8}$ band inversion in GdPtBi by means of infrared spectroscopy.

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S. Polatkan, E. Uykur, I. Mohelsky, J. Wyzula, M. Orlita, C. Shekhar, C. Felser, M. Dressel, A. V. Pronin. 2023-11-14. Exchange gap in GdPtBi probed by magneto-optics. https://doi.org/10.1103/physrevb.108.l201201

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