Fluctuations of persistent current
Mesoscale and Nanoscale Physics
2010-11-22 v2
Abstract
We theoretically analyze equilibrium fluctuations of persistent current (PC) in nanorings. We demonstrate that these fluctuations persist down to zero temperature provided the current operator does not commute with the total Hamiltonian of the system. For a model of a quantum particle on a ring we explicitly evaluate PC noise power which has the form of sharp peaks at frequencies set by the corresponding interlevel distances. In rings with many conducting channels a much smoother and broader PC noise spectrum is expected. A specific feature of PC noise is that its spectrum can be tuned by an external magnetic flux indicating the presence of quantum coherence in the system.
Keywords
Cite
@article{arxiv.1002.3104,
title = {Fluctuations of persistent current},
author = {Andrew G. Semenov and Andrei D. Zaikin},
journal= {arXiv preprint arXiv:1002.3104},
year = {2010}
}
Comments
12 pages, 3 figure