Electronic Excitations in the Bulk of Fractional Quantum Hall States

TL;DR

This paper investigates electronic excitations in the bulk of fractional quantum Hall states using composite fermion theory, revealing how gauge fluctuations influence spectral features and comparing theoretical predictions with experiments.

Contribution

It introduces a detailed analysis of bulk electronic excitations in fractional quantum Hall states, emphasizing the role of gauge fluctuations and extending understanding near half-filling.

Findings

Discrete sharp peaks in spectral function at low filling factors

Broadening of spectral peaks as filling factor approaches 1/2

Agreement with recent experimental observations

Abstract

We analyze electronic excitations (excitations generated by adding or removing one electron) in the bulk of fractional quantum Hall states in Jain sequence states, using composite fermion Chern-Simons field theory. Starting from meanfield approximation in which gauge field fluctuations are neglected, we use symmetry to constrain the possible composite fermion states contributing to electronic Green's function and expect discrete infinitely-sharp peaks in the electronic spectral function. We further consider the electronic excitations in particle-hole conjugate fractional quantum hall states. Gauge field fluctuations play an increasingly important role in the electron spectral function as the filling factor approaches 1/2, and evolve the discrete coherent peaks into a broad continuum even in the absence of impurities. At that limit, we switch to the electron perspective and calculate the electron spectral function via linked cluster approximation from the low to intermediate energy range. Finally, we compare our results with recent experiments.