Infrared study of the multiband low-energy excitations of the topological antiferromagnet MnBi2Te4

Autor: Elvin H. Alizade, Z. A. Jahangirli, Zhiwei Wang, F. Lyzwa, Yongkai Li, Yan Zhang, Nazim Mamedov, Evgeniia Sheveleva, Yugui Yao, Yaomin Dai, Evgueni V. Chulkov, Mikhail M. Otrokov, Christian Bernhard, Vladislav Kataev, Bing Shen, Premysl Marsik, Bing Xu
Rok vydání: 2021
Předmět:
Zdroj: Physical Review B. 103
ISSN: 2469-9969
2469-9950
Popis: With infrared spectroscopy, we studied the bulk electronic properties of the topological antiferromagnet $\mathrm{Mn}{\mathrm{Bi}}_{2}{\mathrm{Te}}_{4}$ with ${T}_{N}\ensuremath{\simeq}25\phantom{\rule{4pt}{0ex}}\mathrm{K}$. With the support of band-structure calculations, we assign the intra- and interband excitations and determine the band gap of ${E}_{g}\ensuremath{\approx}0.17$ eV. We also obtain evidence for two types of conduction bands with light and very heavy carriers. The multiband free-carrier response gives rise to an unusually strong increase of the combined plasma frequency, ${\ensuremath{\omega}}_{\mathrm{pl}}$, below 300 K. The band reconstruction below ${T}_{N}$ yields an additional increase of ${\ensuremath{\omega}}_{\mathrm{pl}}$ and a splitting of the transition between the two conduction bands by about 54 meV. Our study thus reveals a complex and strongly temperature-dependent multiband low-energy response that has important implications for the study of the surface states and device applications.
Databáze: OpenAIRE