Many-particle effects in optical transitions from zero-mode Landau levels in HgTe quantum wells

S. S. Krishtopenko, A. M. Kadykov, S. Gebert, S. Ruffenach, C. Consejo, J. Torres, C. Avogadri, B. Jouault, W. Knap, N. N. Mikhailov, S. A. Dvoretskii, F. Teppe

Published 2019-12-10Version 1

We report on the far-infrared magnetospectroscopy of HgTe quantum wells with inverted band ordering at different electron concentrations. We particularly focus on optical transitions from zero-mode Landau levels, which split from the edges of electron-like and hole-like bands. We observe a pronounced dependence of the transition energies on the electron concentration varied by persistent photoconductivity effect. This is striking evidence that in addition to the already well-documented crystalline and interface asymmetries, electron-electron interactions also have a significant impact on the usual behavior of the optical transitions from zero mode Landau levels.