Partially spin polarized quantum Hall effect in the filling factor range 1/3 < nu < 2/5

TL;DR

This paper predicts the existence of a partially spin-polarized quantum Hall effect between filling factors 1/3 and 2/5, based on composite fermion interactions and energy gap calculations.

Contribution

It introduces a theoretical prediction of partial spin polarization in the fractional quantum Hall regime between 1/3 and 2/5, using composite fermion basis diagonalization.

Findings

Partial spin polarization occurs at several fractions between 1/3 and 2/5.

Excitation gaps are about two orders of magnitude smaller than at 1/3.

Inter-CF interaction is very weak in higher CF levels.

Abstract

The residual interaction between composite fermions (CFs) can express itself through higher order fractional Hall effect. With the help of diagonalization in a truncated composite fermion basis of low-energy many-body states, we predict that quantum Hall effect with partial spin polarization is possible at several fractions between $\nu=1/3$ and $\nu=2/5$. The estimated excitation gaps are approximately two orders of magnitude smaller than the gap at $\nu=1/3$, confirming that the inter-CF interaction is extremely weak in higher CF levels.