Bipartite bound entanglement in continuous variables through degaussification
F. E. S. Steinhoff, M. C. de Oliveira, Jan Sperling, W. Vogel · Physical Review A · 2014
We introduce a class of bipartite entangled continuous variable states that are positive under a partial transposition (PPT) operation, i.e., PPT bound entangled. These states are based on realistic preparation procedures in optical systems, being thus a feasible option to generate and observe genuinely bipartite bound entanglement in high precision experiments. One fundamental step in our scheme is to perform a non-Gaussian operation over a single-mode Gaussian state. This degaussification procedure is achieved through a modified single-photon addition, which is a procedure that is currently being investigated in diverse optical setups. Although dependent on a single-photon detection in an idler channel, the preparation can be made unconditional after a calibration of the apparatus. The detection and proof of bound entanglement is made by means of the range criterion, theory of Hankel operators and Gerschgorin Disk's perturbation theorems.