Josephson junctions as threshold detectors of full counting statistics: open issues
Abstract
I study the dynamics of a Josephson junction serving as a threshold detector of fluctuations which is subjected to a general non-equilibrium electronic noise source whose characteristic is to be determined by the junction. This experimental setup was proposed several years ago as a prospective scheme for determining the full counting statistics of an electronic noise source. Despite intensive theoretical as well as experimental research in this direction the promise has not been quite fulfilled yet and I will discuss what the unsolved issues are. First, I review a general theory for the calculation of the exponential part of the non-equilibrium switching rates of the junction and compare its predictions with previous results found in different limiting cases by several authors. I identify several possible weak points in the previous studies and I report a new analytical result for the linear correction to the rate due to the third cumulant of a non-Gaussian noise source in the limit of a very weak junction damping. The various analytical predictions are then compared with the results of the numerical method developed. Finally, I analyze the status of the experimental data thus far made publicly available with respect to the theoretical predictions and discuss briefly the suitability of the present experimental schemes as regards their potential for measuring the whole of the full counting statistics for non-Gaussian noise sources as well as their relation to the available theories.
- Publication:
-
Journal of Statistical Mechanics: Theory and Experiment
- Pub Date:
- January 2009
- DOI:
- 10.1088/1742-5468/2009/01/P01050
- arXiv:
- arXiv:0807.0387
- Bibcode:
- 2009JSMTE..01..050N
- Keywords:
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- Condensed Matter - Statistical Mechanics;
- Condensed Matter - Mesoscale and Nanoscale Physics
- E-Print:
- 15 pages, 2 figures