A simple and efficient method for characterization of multidimensional Gaussian states is suggested and experimentally demonstrated. Our scheme shows analogies with tomography of finite-dimensional quantum states, with the covariance matrix playing the role of the density matrix and homodyne detection providing Stern-Gerlach-like projections. The major difference stems from a different character of relevant noises: while the statistics of Stern-Gerlach-like measurements is governed by binomial statistics, the detection of quadrature variances corresponds to χ2 statistics. For Gaussian and near Gaussian states the suggested method provides, compared to standard tomography techniques, more stable and reliable reconstructions. In addition, by putting together reconstruction methods for Gaussian and arbitrary states, we obtain a tool to detect the non-Gaussian character of optical signals.
|Titolo:||Effective method to estimate multidimensional Gaussian states|
OLIVARES, STEFANO (Secondo)
|Parole Chiave:||binomial distribution ; covariance matrices ; Gaussian processes ; optical information processing ; quantum optics ; quantum theory ; statistical analysis|
|Settore Scientifico Disciplinare:||Settore FIS/03 - Fisica della Materia|
|Data di pubblicazione:||2009|
|Digital Object Identifier (DOI):||10.1103/PhysRevA.79.032111|
|Appare nelle tipologie:||01 - Articolo su periodico|