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Fermi's golden rule in a mesoscopic metal ring

Peter Kopietz·Axel Voelker
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Abstract

We examine the time-dependent non-equilibrium current in a mesoscopic metal ring threaded by a static magnetic flux phi that is generated by a time-dependent electric field oscillating with frequency omega. We show that in quadratic order in the field there are three fundamentally different contributions to the current. (a) A time-independent contribution which can be obtained from a thermodynamic derivative. (b) A term increasing linearly in time that can be understood in terms of Fermi's golden rule. The derivation of this term requires a careful treatment of the infinitesimal imaginary parts that are added to the real frequency omega when the electric field is adiabatically switched on. (c) Finally, there is also a time-dependent current oscillating with frequency 2 omega. We suggest an experiment to test our results.

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Peter Kopietz, Axel Voelker. 2000-02-03. Fermi's golden rule in a mesoscopic metal ring. https://doi.org/10.1006/spmi.1999.0790

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