Two-dimensional level broadening in the extreme quantum limit

Abstract

Broadening of Landau levels in a two-dimensional electronic system under a strong, perpendicular magnetic field is obtained within a theory in which the broadening and the impurity screening are treated self-consistently. The random-phase approximation is used for the electronic response, and the self-consistent Born approximation is employed for the electron-impurity scattering. The zero-temperature, extreme quantum limit is considered, revealing narrowing of the Landau level width with decreasing filling factor. Possible relevance of these theoretical results to recent experiments on the narrowing of the cyclotron resonance linewidth in space-charge layers is discussed.