Addition Spectrum Oscillations of Fractional Quantum Hall Dots

TL;DR

This paper investigates addition spectrum oscillations in fractional quantum Hall quantum dots using composite fermion theory, revealing periodic behaviors linked to composite fermion transfer and potential detection of fractional charges.

Contribution

It introduces a Hartree composite fermion approach to analyze addition spectrum oscillations in fractional quantum Hall dots, highlighting new oscillation periods and their dependence on confinement and band pinning.

Findings

Period phi_0 oscillations at nu=2/5 and nu=2/3 in sharply confined dots

Period 3*phi_0 oscillations in parabolically confined nu=2/5 dots

Oscillation period varies with magnetic field and confinement conditions

Abstract

Quantum dots in the fractional quantum Hall regime are studied using a Hartree formulation of composite fermion theory. Under appropriate conditions the chemical potential of the dots will oscillate periodically with B due to the transfer of composite fermions between quasi-Landau bands. This effect is analogous to the addition spectrum oscillations which occur in quantum dots in the integer quantum Hall regime. Period phi_0 oscillations are found in sharply confined dots with filling factors nu=2/5 and nu=2/3. Period 3*phi_0 oscillations are found in a parabolically confined nu=2/5 dot. More generally, we argue that the oscillation period of dots with band pinning should vary continuously with B whereas the period of dots without band pinning is phi_0. Finally, we discuss the possibility of detecting fractionally charged excitations using the observed period of addition spectrum oscillations.