Incompressible States of the Interacting Composite Fermions in Negative Effective Magnetic Fields at $\nu=4/13$, 5/17, and 3/10

TL;DR

This paper develops an algorithm to study incompressible fractional quantum Hall states at specific filling factors, revealing new composite fermion pairing mechanisms and calculating their energies and excitation gaps.

Contribution

It introduces a novel algorithm for evaluating basis states of composite fermions in negative magnetic fields and identifies new incompressible states with specific pairing correlations.

Findings

Incompressible states at $ u=3/10$, 4/13, and 5/17 identified.

Chiral p-wave pairing with anti-Pfaffian correlation observed.

Calculated ground state energies and excitation gaps.

Abstract

By developing an algorithm for evaluating the basis states for the composite fermions with negative effective magnetic field, we perform the composite-fermion-diagonalization study for the fully spin-polarized fractional quantum Hall states at the filling factors $\nu = 3/10$, 4/13, and 5/17 in the range $2/7 <\nu < 1/3$. These observed states correspond to partially filled second effective Landau level, for the composite fermions carrying four vortices, with filling factor $\bar{\nu} = 1/2$, 1/3, and 2/3 respectively, analogous to the previously studied states of composite fermions with two attached vortices in the range $1/3 <\nu <2/5$. We show that the character of these states in the range $2/7 <\nu < 1/3$ replicates the same for the states in the range $1/3 <\nu <2/5$ having identical $\bar{\nu}$: Chiral p-wave pairing with anti-Pfaffian correlation of composite fermions carrying six quantized vortices produces incompressible state at $\nu = 3/10$; an unconventional interaction between composite fermions, resulting from the suppression of fermion pairs with relative angular momentum three and producing fractional quantum Hall effect of composite fermions in the second effective Landau level with $\bar{\nu} =1/3$ and its particle-hole conjugate filling factor 2/3, reproduces incompressible states at $4/13$ and $5/17$ filling factors. We further estimate the thermodynamic limit of the ground state energies and calculate the lowest energy gap for neutral collective excitations of these states.