Resource theory of quantum nonGaussianity and Wigner negativity
Abstract
We develop a resource theory for continuousvariable systems grounded on operations routinely available within current quantum technologies. In particular, the set of free operations is convex and includes quadratic transformations and conditional coarsegrained measurements. The present theory lends itself to quantify both quantum nonGaussianity and Wigner negativity as resources, depending on the choice of the freestate set—i.e., the convex hull of Gaussian states or the states with positive Wigner function, respectively. After showing that the theory admits no maximally resourceful state, we define a computable resource monotone—the Wigner logarithmic negativity. We use the latter to assess the resource content of experimentally relevant states—e.g., photonadded, photonsubtracted, cubicphase, and cat states—and to find optimal working points of some resource concentration protocols. We envisage applications of this framework to subuniversal and universal quantum information processing over continuous variables.
 Publication:

Physical Review A
 Pub Date:
 November 2018
 DOI:
 10.1103/PhysRevA.98.052350
 arXiv:
 arXiv:1804.05763
 Bibcode:
 2018PhRvA..98e2350A
 Keywords:

 Quantum Physics
 EPrint:
 18 pages, 10 figures, close to published version