Electrodynamics of MnBi2Te4 intrinsic magnetic topological insulators

• DOI: 10.1038/s41427-022-00429-w
• Publication Date: 2022-10-14T01:02:49Z
• Authors: Luca Tomarchio; Lorenzo Mosesso; Salvatore Macis; Antonio Grilli; Martina Romani; Mariangela Cestel...; Kejing Zhu; Xiao Feng; Michele Zacchigna; Massimo Petrarca; Ke He; Stefano Lupi
• Keywords: Topological insulator; Optical conductivity; Surface States; T-symmetry

Abstract We report on the electrodynamics of MnBi 2 Te 4 thin films, an intrinsic magnetic topological material. study its optical conductivity from terahertz (THz) to ultraviolet (UV) frequencies as a function film thickness, highlighting presence surface states superimposed bulk response. For thinnest film, where charge transport is dominated by Dirac states, we investigate effect phase transition high-temperature protected state low-temperature (time-reversal broken) measuring across Néel temperature. At low temperatures, breaking time reversal symmetry affects conductivity, indicating that magnetic-induced gap opens below T N .