Novel Families of Fractional Quantum Hall States: Pairing of Composite Fermions

TL;DR

This paper introduces a new family of fractional quantum Hall states characterized by pairing correlations among quasiparticles, explaining recent experimental observations at unexpected filling factors.

Contribution

It proposes a novel theoretical framework for FQH states based on pairing of composite fermions, expanding beyond traditional Laughlin correlations.

Findings

Pairing correlations can produce FQH states at observed filling factors

Behavior of QP-QP pseudopotential V_QP(L') is crucial for state formation

Numerical studies support the pairing mechanism as explanation for experimental data

Abstract

Fractional quantum Hall (FQH) states have recently been observed at unexpected values of the filling factor nu. Here we interpret these states as a novel family of FQH states involving pairing correlations rather than Laughlin correlations among the quasiparticles (QP's). The correlations depend upon the behavior of the QP-QP pseudopotential V_QP(L'), the interaction energy of a pair as a function of the pair angular momentum L'. This behavior, known from numerical studies of small systems, is used to demonstrate that pairing correlations give rise to FQH states at the experimentally observed values of nu.