FABRY-PEROT RESONANCE IN AHARONOV-BOHM CONDUCTANCE OSCILLATION AT FINITE TEMPERATURES

The line shape of Fabry-Perot resonance in Aharonov-Bohm conductance o scillation in a mesoscopic ring is calculated as a function of magneti c phase shift at finite temperatures. The case of the maximum coupling between the ring and leads is considered. It is shown that the 2 pi p eriodic series of resonance peaks with height e(2)/h and width zero at temperature T = O is broadened as a result of energy dispersion. The peak height is almost kept invariant below 10 K. This is because Fermi energy is far larger than thermal breadth at the step of the Fermi fu nction in this temperature range. Implications of these results are di scussed in relation to application to small-area-single-flux-quantum d evices.