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arXiv · 0906.2831

Circulating currents and magnetic moments in quantum rings

Michele Cini·Enrico Perfetto·Gianluca Stefanucci
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Abstract

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.

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Michele Cini, Enrico Perfetto, Gianluca Stefanucci. 2009-06-16. Circulating currents and magnetic moments in quantum rings. https://arxiv.org/abs/0906.2831

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