Temperature-Induced Topological Phase Transition in HgTe Quantum Wells Auteur(s): Kadykov A., Krishtopenko S., Jouault B., Desrat W., Knap W., Ruffenach S., Consejo C., Torres Jeremie, Morozov S. V., Mikhailov N. N., Dvoretskii S. A., Teppe F.
Ref HAL: hal-01740166_v1 Ref Arxiv: 1710.06666 DOI: 10.1103/PhysRevLett.120.086401 WoS: WOS:000425738500007 Ref. & Cit.: NASA ADS Exporter : BibTex | endNote 29 Citations Résumé: We report a direct observation of temperature-induced topological phase transition between trivial and topological insulator in HgTe quantum well. By using a gated Hall bar device, we measure and represent Landau levels in fan charts at different temperatures and we follow the temperature evolution of a peculiar pair of "zero-mode" Landau levels, which split from the edge of electron-like and hole-like subbands. Their crossing at critical magnetic field Bc is a characteristic of inverted band structure in the quantum well. By measuring the temperature dependence of Bc, we directly extract the critical temperature Tc at which the bulk band-gap vanishes and the topological phase transition occurs. Above this critical temperature, the opening of a trivial gap is clearly observed. Commentaires: 5 pages + Supplemental Materials |