Ballistic composite fermions in semiconductor nanostructures

[摘要] We report the results of two fundamental transport measurements at a Landau level filling factor nu of 1/2. The well-known ballistic electron transport phenomena of quenching of the Hall effect in a mesoscopic cross-junction and negative magnetoresistance of a constriction are observed close to B=0 and nu=1/2. The experimental results demonstrate semiclassical charge transport by composite fermions, which consist of electrons bound to an even number of flux quanta.

[关键词] LANDAU-LEVEL;HALL;HIERARCHY;STATES;WIRES