Local PT-symmetric evolutions on separable states and violation of no-signaling

Abstract

We show that local P T -symmetric evolutions can lead to violation of the no-signaling principle for separable and even classically correlated bipartite shared quantum states. For classically correlated states, specially chosen P T -symmetric operations from a set of zero volume can also preserve the principle. The violations can be removed by using a CP T inner product instead of the traditional one.