N-orbital model for a two-dimensional disordered system in a strong magnetic field
- 1 January 1984
- journal article
- Published by EDP Sciences in Journal de Physique Lettres
- Vol. 45 (14) , 713-718
- https://doi.org/10.1051/jphyslet:019840045014071300
Abstract
An N-orbital model is considered for a two-dimensional disordered system in a strong perpendicular magnetic field. The Hamiltonian is projected on the lowest Landau level. In a field theoretical formulation the large N limit result corresponds to the translationally invariant saddle point for this model. A diagrammatic expansion in powers of 1/N is performed around the large N limit. The conductivity is calculated up to order 1/N2. No mobility edge is found in this expansion. The result is consistent with the non-linear unitary σ-model and independent of magnetic field and disorder strength if the energy is measured in units of the bandwidthKeywords
This publication has 5 references indexed in Scilit:
- Exact density of states for lowest Landau level in white noise potential superfield representation for interacting systemsZeitschrift für Physik B Condensed Matter, 1983
- Electron Delocalization by a Magnetic Field in Two DimensionsPhysical Review Letters, 1983
- Disordered system withn orbitals per site: Lagrange formulation, hyperbolic symmetry, and goldstone modesZeitschrift für Physik B Condensed Matter, 1980
- Effects of spin interactions in disordered electronic systems: Loop expansions and exact relations among local gauge invariant modelsZeitschrift für Physik B Condensed Matter, 1980
- Generalized non-linear σ-models with gauge invarianceNuclear Physics B, 1980