On the response of composite fermions to weak electrostatic potentials

TL;DR

This paper investigates how composite fermions in two-dimensional electron systems respond to static electrostatic perturbations near filling fraction 1/2, revealing significant differences from non-interacting models and highlighting unresolved questions about magneto-resistivity behavior.

Contribution

It demonstrates the inadequacy of treating composite fermions as non-interacting and challenges recent theories explaining magneto-resistivity near /2.

Findings

Response to static perturbations is singularly different near /2.

Non-interacting composite fermion models are insufficient.

The origin of magneto-resistivity behavior remains unresolved.

Abstract

We establish that the response to static perturbations of two-dimensional electron systems (2DESs), exposed to magnetic field B, in states with the Landau-level filling fractions \nu close to one such as 1/2, is singularly different from that of 2DESs at small |B|. Thus in addition to demonstrating the sever inadequacy of the treatment of composite fermions as non-interacting particles, we show, in contradiction to a recent theoretical finding, that the physical origin of the observed behaviour of the dc longitudinal magneto-resistivity for \nu close to 1/2 in periodically modulated 2DESs remains to be determined.