Addition Spectrum Oscillations of Fractional Quantum Hall Dots

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.