Control of the persistent currents in two interacting quantum rings   through the Coulomb interaction and inter-ring tunneling
  The persistent current in two vertically coupled quantum rings containing few electrons is studied. We find that the Coulomb interaction between the rings in the absence of tunneling affects the persistent current in each ring and the ground state configurations. Quantum tunneling between the rings alters significantly the ground state and the persistent current in the system. 
L. K. Castelano, G.-Q. Hai, B. Partoens and F. M. Peeters