Entangled quantum state discrimination using a pseudo-Hermitian system

Abstract

We demonstrate how to discriminate two non-orthogonal, entangled quantum states which are slightly different from each other by using a pseudo-Hermitian system. The positive definite metric operator which makes the pseudo-Hermitian system fully consistent with quantum theory is used for such a state discrimination. We further show that non-orthogonal states can evolve through a suitably constructed pseudo-Hermitian Hamiltonian to orthogonal states. Such an evolution ceases at exceptional points of the pseudo-Hermitian system. © 2012 IOP Publishing Ltd.