Flavor altering excitations of composite fermions

TL;DR

This paper explores flavor-changing excitations of composite fermions, revealing a hierarchy of excitations involving vortex shedding, which explains experimental observations of multiple excitation modes in fractional quantum Hall systems.

Contribution

It introduces a general framework for flavor-changing excitations of composite fermions, extending previous models to include vortex shedding and explaining experimental findings.

Findings

Existence of a ladder of flavor-changing excitations.

Lowest energy excitations involve no flavor change.

Highest energy excitations involve complete vortex shedding.

Abstract

Past theoretical studies have considered excitations of a given flavor of composite fermions across composite-fermion quasi-Landau levels. We show that in general there exists a ladder of flavor changing excitations in which composite fermions shed none, some, or all of their vortices. The lowest energy excitations are obtained when the composite fermions do not change their flavor, whereas in the highest energy excitations they are stripped of all of their vortices, emerging as electrons in the final state. The results are relevant to the intriguing experimental discovery of Hirjibehedin {\em et al.} (cond-mat/0306152) of coexisting excitation modes of composite fermions of different flavor in the filling factor range $1/3>\nu\geq 1/5$.