RECOVERY OF THE PERSISTENT CURRENT-INDUCED BY THE ELECTRON-ELECTRON INTERACTION IN MESOSCOPIC METALLIC RINGS

Persistent currents in mesoscopic metallic rings induced by static mag netic fields are investigated by means of a Hamiltonian which incorpor ates diagonal disorder and the electron-electron interaction through a Hubbard term (U). Correlations are included up to second order pertur bation theory which is shown to work accurately for U of the order of the hopping integral. If disorder is not very strong, interactions inc rease the current up to near its value for a clean metal. Averaging ov er ring lengths eliminates the first Fourier component of the current and reduces its value, which remains low after interactions are includ ed. Copyright (C) 1996 Elsevier Science Ltd.