2009/06/16 by Michele Cini, Enrico Perfetto, Cini, Michele +3
Physics and Astronomy · #FOS: Physical sciences #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #cond-mat.mes-hall
paper · pdf · doi:10.48550/arxiv.0906.2831
submitted for publication
arxiv created 2009/06/16 · arxiv updated 2009/12/01
In circuits containing closed loops the operator for the current is determined by charge conservation up to an arbitrary divergenceless current. In this work we propose a formula to calculate the magnetically active circulating current I\rm ring flowing along a quantum ring connected to biased leads. By \em gedanken experiments we argue that I\rm ring can be obtained from the response of the gran-canonical energy of the ring to an external magnetic flux. The results agree with those of the conventional approach in the case of isolated rings. However, for connected rings I\rm ring cannot be obtained as a linear combination of bond currents.