Enhancing the capacity of quantum dense coding from correlated amplitude damping channel via non-Hermitian operation

Abstract

Using the non-Hermitian operation approach, we propose a scheme to protect and enhance quantum dense coding from correlated amplitude damping (AD) decoherence. In contrast to the results of memoryless AD channel, we show that the memory effects play a significant role in the suppression of quantum dense coding sudden death. Moreover, we find that the damaged quantum dense coding can be effectively enhanced by using the non-Hermitian operation. Furthermore, the freezing phenomenon of quantum dense coding can be detected by using the optimal non-Hermitian operation.