Phenomenological understanding of a transport regime with reflection symmetry in the quantum Hall system in a composite-fermion picture

Abstract

In this paper, we present a phenomenological picture based on the composite fermion theory, in responding to the recent discovery by Shahar et al. of a new transport regime near the transition from a $\nu=1$ quantum Hall liquid to a Hall insulator(ref[8]). In this picture, the seemingly unexpected reflection symmetry in the longitudinal resistivity $\rho_{xx}$ can be understood clearly as due to the symmetry of the gapful excitations which dominate $\sigma_{xx}$ across the transition, and the abrupt change in $\sigma_{xy}$ at the transition. The parameter $\alpha$ in the linear fit of $\nu_0(T)$ in ref[8] is also given a simple physical meaning and the effective mass can be calculated from $\alpha$, which gives a reasonable value of several electron band mass. When taking into account the result of network model, the almost invariant Hall resistivity $\rho_{xy}$ across the transition is also well-understood.