Tuesday, July 23, 2013

1307.5739 (A. Komnik et al.)

Full counting statistics of persistent current    [PDF]

A. Komnik, G. W. Langhanke
We develop a method for calculation of charge transfer statistics of persistent current in nanostructures. We consider a simply connected one-dimensional system (a wire) with arbitrary interactions and develop a procedure for the calculation of FCS of persistent currents when the wire is closed into a ring via a weak link. For the non-interacting system we derive a general formula in terms of the two-particle Green's functions. We show that, contrary to the conventional tunneling contacts, the resulting cumulant generating function has a doubled periodicity as a function of the counting variable. We apply our general formula to short tight-binding chains and show that the FCS perfectly reproduces the known evidence for the persistent current. Its second cumulant turns out to be maximal at the switching points and vanishes identically at zero temperature. Furthermore, we consider a system with an embedded Anderson impurity and employing a self-energy approximation find an overall suppression of persistent current as well as of its noise.
View original: http://arxiv.org/abs/1307.5739

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