Internal structure of a Landau band induced by a lateral superlattice: a glimpse of Hofstadter's butterfly
Sektion Physik, LMU München - Geschw. Scholl Platz 1, D-80539
2 Department of Electronics, University of Glasgow - Glasgow G12 8QQ, UK
Accepted: 1 February 1996
Short-period square lateral superlattices are fabricated on a two-dimensional electron gas located close to the sample surface. For weak potential modulation, band conductivity dominates the low-field magnetoresistance leading to pronounced commensurability oscillations. For increasing potential modulation, band conductivity breaks down and scattering conductivity dominates indicating our beginning to resolve the internal structure of a Landau band. For strong potential modulation the maxima of the Shubnikov-de Haas oscillations split up into submaxima related to the number of flux quanta penetrating a unit cell.
PACS: 71.25.-s – Nonlocalized single-particle electronic states / 73.20.Dx – Electron states in low-dimensional structures (including quantum wells, superlattices, layer structures, and intercalation compounds) / 73.50.Jt – Galvanomagnetic and other magnetotransport effects (including thermomagnetic effects)
© EDP Sciences, 1996