Two-subband system in quantizing magnetic field: Probing many-body gap by non-equilibrium phonons
Physica E: Low-Dimensional Systems and Nanostructures
We study the many-body effects in a two-subband quasi-two-dimensional electron system in a quantizing magnetic field at filling factor three. A manifestation of these effects in the phonon absorption spectroscopy is discussed. The electron system is mapped onto a two-level system with the separation between levels determined by the intersubband splitting and the cyclotron energy. The electron–electron interaction enhances the excitation gap, which exists at all values of the interlevel splitting. This results in a single-peak structure of the phonon absorption rate as a function of magnetic field, instead of the double-peak structure for non-interacting electrons.
Copyright © 2002 Elsevier. NOTICE: this is the pre-print version of a work that was accepted for publication in Physica E. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Physica E Volume 15, Issue 3, pp. 202–210 (2002). DOI: 10.1016/S1386-9477(02)00554-4
Vol. 15 (3), pp. 202 - 210