The magnetic configuration of edge channels near the boundary of a quasi-two-dimensional electron gas in the integer quantum Hall regime is studied in the Hartree-Fock approximation. In earlier work [J. Dempsey, B. Y. Gelfand, and B. I. Halperin, Phys. Rev. Lett. 70, 3639 (1993)] electron-electron interactions were found to cause a spin-polarizing transition of the outermost edge states. These calculations are extended by including a nonequilibrium occupation of spin levels. A sudden reversal of edge-channel positions is predicted at values of the chemical-potential difference much smaller than the enhanced spin splitting at the edges. The crossings, which arise when edge channels switch position in open systems, are identified as solitonlike, one-dimensional magnetic domain walls. The interaction between these magnetic defects is investigated. Possible consequences and verification by experiment of the predictions are discussed.
ASJC Scopus subject areas
- Condensed Matter Physics