2018/04/30 by Francesco Albarelli, Marco G. Genoni, Matteo G. A. Paris +1 · 2 citations
Physics and Astronomy · #quant-ph
paper · pdf · doi:10.1103/physreva.98.052350
published as Phys. Rev. A 98, 052350 (2018) · 18 pages, 10 figures, close to published version
arxiv created 2018/12/04 · arxiv updated 2018/12/05
We develop a resource theory for continuous-variable 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 coarse-grained measurements. The present theory lends itself to quantify both quantum non-Gaussianity and Wigner negativity as resources, depending on the choice of the free-state 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., photon-added, photon-subtracted, cubic-phase, and cat states --- and to find optimal working points of some resource concentration protocols. We envisage applications of this framework to sub-universal and universal quantum information processing over continuous variables.