Direct Measurement of the g-Factor of Composite Fermions

TL;DR

This paper reports a direct measurement of the composite fermion g-factor in fractional quantum Hall states, revealing its strong renormalization by interactions and dependence on electronic filling factor.

Contribution

The study provides the first direct measurement of the composite fermion g-factor and shows its variation with magnetic field and filling factor.

Findings

g-factor is heavily renormalized by interactions

g-factor varies with electronic filling factor

Linear dependence of activation gap on magnetic field

Abstract

The activation gap $\Delta$ of the fractional quantum Hall states at constant fillings $\nu =2/3$ and 2/5 has been measured as a function of the perpendicular magnetic field $B$. A linear dependence of $\Delta$ on $B$ is observed while approaching the spin polarization transition. This feature allows a direct measurement of the $g$-factor of composite fermions which appears to be heavily renormalized by interactions and strongly sensitive to the electronic filling factor.