Improving the capacity of quantum dense coding by weak measurement and reversal measurement

Abstract

A protocol of quantum dense coding protection of two qubits is proposed in amplitude damping (AD) channel using weak measurement and reversal measurement. It is found that the capacity of quantum dense coding under the weak measurement and reversal measurement is always greater than that without weak measurement and reversal measurement. When the protocol is applied, for the AD channels with different damping coefficient, the result reflects that quantum entanglement can be protected and quantum dense coding becomes successful.In recent years, with the development of quantum mechanics and the establishment of quantum information science, quantum entanglement becomes a new research hotspot of theoretical physics. Quantum entanglement, which is a key part of quantum information processing[1], including quantum teleportation[2-3], quantum computing[4], quantum cryptography[5], quantum dense coding[6] and quantum secret sharing [7]. However, in realistic quantum information processing, entanglement is inevitably affected by the interaction between the system and environment, which leads to degradation. Furthermore, entanglement sudden death (ESD) [8][9][10][11] will appear in this case. Thus, it is very important to protect entanglement in quantum information processing.

Quantum dense coding with gravitational cat states

“…In the literature, several studies have both theoretically proposed and experimentally demonstrated the concept of dense coding (see, e.g., [9][10][11][12][13][14][15][16][17] and references quoted therein). Interestingly, different methods have been presented to protect the quantum advantages of dense coding under decoherence for a relatively long time [18][19][20][21][22][23], such as choosing the proper initial channel state [24,25], employing different configurations for the external noise [26,27], and applying the quantum weak measurement (QWM) operation [28][29][30].…”

Improving the capacity of quantum dense coding via non-Hermitian operation

“…Recently, Tian and Zhang [36] proposed a scheme to improve the capacity of super dense coding by using weak measurement (WM) and quantum measurement reversal (QMR) in the AD channel. The basic idea can be expressed as: WM −→ AD channel −→ QMR −→ super dense coding.…”

Quantum Teleportation and Dense Coding in Multiple Bosonic Reservoirs

“…It was shown that their quantum advantages may exist for a relatively long time by choosing specific channel states [ 24 , 25 ], by using the desired features (the non-Markovianity, the correlated actions, etc.) of the noises [ 26 , 27 , 28 ], or by applying active operations, such as local filtering operations [ 27 ] and weak measurements [ 29 , 30 ].…”