Full Counting Statistics of Non-Commuting Variables: the Case of Spin Counts
Abstract
We discuss the Full Counting Statistics of non-commuting variables with the measurement of successive spin counts in non-collinear directions taken as an example. We show that owing to an irreducible detector back-action, the FCS in this case may be sensitive to the dynamics of the detectors, and may differ from the predictions obtained with using a naive version of the Projection Postulate. We present here a general model of detector dynamics and path-integral approach to the evaluation of FCS. We concentrate further on a simple "diffusive" model of the detector dynamics where the FCS can be evaluated with transfer-matrix method. The resulting probability distribution of spin counts is characterized by anomalously large higher cumulants and substantially deviates from Gaussian Statistics.
Keywords
Cite
@article{arxiv.cond-mat/0510215,
title = {Full Counting Statistics of Non-Commuting Variables: the Case of Spin Counts},
author = {Antonio Di Lorenzo and Gabriele Campagnano and Yuli V. Nazarov},
journal= {arXiv preprint arXiv:cond-mat/0510215},
year = {2007}
}
Comments
11 pages, 3 figures