Enhancing the nonlocal advantage of quantum coherence by local parity-time ( PT )-symmetric operation

We propose a novel method to enhance the capacity of quantum dense coding under amplitude damping noise using non-Hermitian operations. With the assistance of non-Hermitian operations, we show that the capacity of quantum dense coding can always be larger than 1 for any two-qubit states. In particular, the non-Hermitian operation can improve quantum dense coding more efficiently in the case of strong decoherence strength than those with small decoherence strength. Our results shed new light on the protection of quantum dense coding in a quantum environment.

Section: Introductionmentioning

confidence: 99%

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

Leng,

Chen

2023

“…In [13] the authors found that the no-signalling principle can be violated when applying the local PT -symmetric operation on one of the entangled particles. More recently, it has also been shown that PT -symmetric operation can be used to suppress the decoherence of amplitude damping model [14][15][16][17][18][19][20][21], and slow down the decoherence of the pure phase damping model [22].…”

Section: Introductionmentioning

confidence: 99%

Improving parameter estimation precision by parity-time symmetric operation

Chen¹,

He²,

Wang³

2022

The enhancement of the precision of phase estimation in quantum metrology is investigated by employing parity-time ( P T ) symmetric operation. We derive the exact expressions of the quantum Fisher information (QFI) and the success probability of the phase estimation for an exactly solving model consisting of a qubit interacting with a structured reservoir. Special attention is paid to the two schemes, i.e. pre-and post- P T symmetric operations. We show that the QFI can be obviously enhanced by means of the P T symmetric operation in different regimes. In addition, we also show that the magnitude of the decoherence involved in the P T symmetric operation can be a general complex number, which extends the applicable scope of the P T symmetric operation approach.

“…In [31], the authors found that the no-signalling principle can be violated when applying the local non-Hermitian operation on one of the entangled particles. More recently, it has also been shown that non-Hermitian operation can be used to suppress the decoherence of amplitude damping model [32][33][34][35][36], and slow down the decoherence of pure phase damping model [37], and so on. Moreover, recent research [38] has shown that the qubit-qubit entanglement can obviously be enhanced by the means of either local prior or post non-Hermitian operations.…”

Section: Introductionmentioning

confidence: 99%

Protecting qubit-qutrit entanglement via non-Hermitian operation

Chang

Zhao

et al. 2021

Entangled states with high-dimensional systems have been investigated widely because of their extended possibilities. We investigate the entanglement protection of a qubit-qutrit system under amplitude damping decoherence by employing non-Hermitian operation. We find that the qubit-qutrit entanglement decays monotonically as the decoherence strength increases, and may go through a sudden death for strong decoherence strength. However, we can completely defeat amplitude damping decoherence and recover or even magnify the initial entanglement perfectly by means of non-Hermitian operation. In particular, the non-Hermitian operation can protect entanglement more efficiently in the case of strong decoherence strength than those with small decoherence strength.