Addition-spectrum oscillations in fractional quantum Hall dots

Quantum dots in the fractional quantum Hall regime are studied using a Hartree formulation of the 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 that occur in quantum dots in the integer quantum Hall regime. Period ${\phi }_0$ oscillations are found in sharply confined dots with filling factors $\nu =2/5\mathrm{}$ and $\nu =2/3.\mathrm{}$ Period $3{\phi }_0$ oscillations are found in a parabolically confined $\nu =2/5\mathrm{}$ 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.