Title:	A measure of non-Gaussianity for quantum states
Authors:	Ivan, Solomon J. Sanjay Kumar, M. Simon, R.
Keywords:	Non-Gaussianity measure Quasiprobability · Q-function Wehrl entropy Photon-added thermal states
Issue Date:	Jun-2012
Publisher:	Springer
Citation:	Quantum information processing, 2012, Vol.11, p853-872
Abstract:	We propose a measure of non-Gaussianity for quantum states of a system of n oscillator modes. Our measure is based on the quasi-probability Q(α), α ∈ Cn. Since any measure of non-Gaussianity is necessarily an attempt at making a quantitative statement on the departure of the shape of theQfunction from Gaussian, any good measure of non-Gaussianity should be invariant under transformations which do not alter the shape of theQfunctions, namely displacements, passage through passive linear systems, and uniform scaling of all the phase space variables: Q(α) → λ2nQ(λα). Our measure which meets this ‘shape criterion’ is computed for a fewfamilies of states, and the results are contrasted with existing measures of non-Gaussianity. The shape criterion implies, in particular, that the non-Gaussianity of the photon-added thermal states should be independent of temperature.
Description:	Restricted Access. An open-access version is available at arXiv.org (one of the alternative locations)
URI:	http://hdl.handle.net/2289/4570
ISSN:	1570-0755 1573-1332 (Online)
Alternative Location:	http://arxiv.org/abs/0812.2800 http://dx.doi.org/10.1007/s11128-011-0314-2
Copyright:	2012 Springer Science+Business Media, LLC
Appears in Collections:	Research Papers (LAMP)

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