Enhancement of quantum entanglement by local non-Hermitian operation under various decoherence sources

Abstract

Abstract We examine the validity and limitation of the local non-Hermitian operation in the enhancement of qubit-qubit entanglement from various decoherence sources. We derive the exact expressions of concurrence quantifying entanglement for an exactly solving model consisting of two qubits interacting with various decoherence sources. we show explicitly that the local non-Hermitian operation indeed helps for enhancing quantum entanglement from amplitude damping, but not for phase damping. Finally, we give a brief discussion of the physical explanation for our scheme.