Ballistic Composite Fermions in Semiconductor Nanostructures

TL;DR

This paper presents experimental evidence of ballistic transport phenomena in semiconductor nanostructures at filling factor 1/2, demonstrating semi-classical behavior of composite fermions through specific transport measurements.

Contribution

It provides the first direct experimental observation of ballistic composite fermion transport phenomena in semiconductor nanostructures.

Findings

Observation of Hall effect quenching in a mesoscopic cross-junction.

Detection of negative magnetoresistance in a constriction.

Confirmation of semi-classical composite fermion behavior.

Abstract

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 semi-classical charge transport by composite fermions, which consist of electrons bound to an even number of flux quanta.