Équipe de Recherche en Physique de l'Information Quantique


Abstract = {We have measured the magnetoresistance of a variety of structures to search for effects associated with composite fermions (CF) near the Landau filling factor v = 1/2. We find evidence for effects due to randomization of semiclassical ballistic CF trajectories. These produce magnetoresistance features similar to those observed near zero magnetic field. However, we were not able to reproduce the recent CF magnetic focusing experiment despite using devices of very similar quality to those used in the original experiment. We also searched, without success, for phenomena due to phase coherence of CF. The relative ease with which the various magnetoresistance effects are seen in CF is discussed, in part with the aid of semiclassical simulations. It is discovered that inhomogeneities of carrier density cause the magnetoresistance anomalies to be smeared out, largely as a result of spatial variations in the effective magnetic field experienced by the CF. We find also that experiments which are based on randomization of trajectories are more resilient to this spatial variation.},
Author = {Sachrajda, A. and Feng, Y. and Delage, A. and Kelly, P. and Carmona, H. and Main, P.C. and Eaves, L.},
Document_Type = {Article},
Journal = {Journal of Physics Condensed Matter},
Number = {17},
Pages = {3019-3032},
Source = {Scopus},
Title = {Investigations of composite fermions in semiconductor nanostructures},
Url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0030127784&partnerID=40&md5=9b1bf0be9978d24f31cdf96673373a01},
Volume = {8},
Year = {1996},
Bdsk-Url-1 = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0030127784&partnerID=40&md5=9b1bf0be9978d24f31cdf96673373a01}}