Amplifying the capacity of quantum super dense coding by non-Hermitian operations under phase decoherence source

Abstract

We study the dynamic behavior of quantum super dense coding between two uncoupled qubits, which are immersed in a common Ohmic environment. We examine the validity of local non-Hermitian operations in the amplification of quantum super dense coding. In particular, using analytical and numerical investigations, we show explicitly that the capacity of quantum super dense coding can be greatly amplified with the assistance of a local non-Hermitian operation, i.e. a parity-time symmetric operation. This sheds new light on the protection of quantum super density.