Charge fluctuations in a quantum point contact attached to a superconducting lead
Abstract
We show how to calculate the charge noise spectrum in a normal mesoscopic conductor, which is capacitively coupled to a macroscopic gate, when this conductor is attached to L normal leads and M superconducting leads, the only restriction being that the superconducting leads must be at the same chemical potential. We then proceed to examine results for a quantum point contact (QPC) in a normal lead connecting to a superconductor. Of interest is the fluctuating current in a gate capacitively coupled to a QPC. The results are compared with the case when all leads are normal. We find a doubling of the equilibrium charge fluctuations and a large enhancement (>2) in the current noise spectrum to first order in |eV|, when a channel in the QPC is opening.
Keywords
Cite
@article{arxiv.cond-mat/9907240,
title = {Charge fluctuations in a quantum point contact attached to a superconducting lead},
author = {Andrew M. Martin and Thomas Gramespacher and Markus Buttiker},
journal= {arXiv preprint arXiv:cond-mat/9907240},
year = {2009}
}
Comments
4 pages, 3 figures