Persistent current in an artificial quantum-dot molecule

Using an exact diagonalization technique within a generalized Mott-Hubbard Hamiltonian, we predict the existence of a ground-state persistent current in coherent two-dimensional semiconductor quantum-dot arrays pierced by an external magnetic flux. The calculated persistent current, which arises from the nontrivial dependence of the ground-state energy on the external flux, exists in isolated arrays without any periodic boundary condition. The sensitivity of the calculated persistent current to interaction and disorder is shown to reflect the intricacies of various Anderson-Mott-Hubbard quantum phase transitions in two-dimensional systems.