A tight bound on negativity of superpositions
School of physics and optoelectronic technology, Dalian University of Technology, 116024, Dalian, P.R. China
Corresponding author: a firstname.lastname@example.org
Revised: 25 February 2010
Published online: 4 June 2010
By a variational definition of the entanglement measure – negativity, we derive an upper bound of negativity of superpositions in terms of the negativities of the quantum states being superposed. It is shown that the upper bound has a simple formulation. In particular, in many cases the upper bound is tighter than the previous bounds.
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2010