Compressibility of a quantum Hall system at $\nu = 1/2$

TL;DR

This paper investigates the compressibility of a quantum Hall system at filling factor 1/2, showing that despite composite fermions being electrically neutral with a dipole moment, the system's long-wavelength compressibility remains finite.

Contribution

It provides a theoretical argument that the long-wavelength compressibility of the $ u=1/2$ quantum Hall system is finite, challenging previous assumptions about neutrality and compressibility.

Findings

Long-wavelength compressibility is finite at $ u=1/2$

Composite fermions' neutrality does not imply zero compressibility

Theoretical analysis of quantum Hall system at $ u=1/2$

Abstract

Despite the fact that composite fermions may be regarded as electrically neutral objects at Landua-level filling factor $\nu=1/2$, carrying only an electric dipole moment, we argue that the long-wavelength compressibility of the system is finite.