Non linear conductivity and collective charge excitations in the lowest Landau level

TL;DR

This paper explores how non-linear conductivity measurements can reveal collective charge excitations and modes in fractional quantum Hall systems, potentially enabling electrical probing of these phenomena.

Contribution

It introduces a theoretical framework linking non-linear photoconductivity to charge susceptibility, predicting new phenomena like negative photoconductivity and zero resistance states.

Findings

Negative photoconductivity in incompressible phases.

Zero resistance states with spontaneous internal electric fields.

Probing composite fermion excitations via non-linear conductivity.

Abstract

For weakly disordered fractional quantum Hall phases, the non linear photoconductivity is related to the charge susceptibility of the clean system by a Floquet boost. Thus, it may be possible to probe collective charge modes at finite wavevectors by electrical transport. Incompressible phases, irradiated at slightly above the magneto-roton gap, are predicted to exhibit negative photoconductivity and zero resistance states with spontaneous internal electric fields. Non linear conductivity can probe composite fermions' charge excitations in compressible filling factors.