Transition from Free to Interacting Composite Fermions away from $\nu$=1/3

TL;DR

This paper investigates how composite fermions transition from free to interacting states near filling factor 1/3, revealing significant interaction effects and potential links to higher order quantum Hall states.

Contribution

It provides experimental evidence of the transition from free to interacting composite fermions away from ν=1/3, highlighting the increasing importance of interactions in this regime.

Findings

Departure from non-interacting composite fermion behavior in 2/7<ν<2/5

Observation of a transition to interacting composite fermions

Possible connection to higher order fractional quantum Hall states

Abstract

Spin excitations from a partially populated composite fermion level are studied above and below $\nu=1/3$. In the range $2/7<\nu<2/5$ the experiments uncover significant departures from the non-interacting composite fermion picture that demonstrate the increasing impact of interactions as quasiparticle Landau levels are filled. The observed onset of a transition from free to interacting composite fermions could be linked to condensation into the higher order states suggested by transport experiments and numerical evaluations performed in the same filling factor range.