A quantum beat of quantum discord induced by the number of qubits in non-Markovian environments

Abstract

We investigate the protection of the quantum discord of two qubits, individually originated by two generalized amplitude-damping models. Here, each generalized amplitude-damping model consists of N non-interacting qubits interacting with a common zero-temperature reservoir. First, for initial states with extended Werner-like states, we find that the robust quantum discord of two qubits against decoherence can be obtained by controlling the number of qubits in the reservoir. More interestingly, we find that a quantum beat for quantum discord can occur when both the number of qubits in each reservoir is large and when the number of qubits have a tiny difference, even in the resonant case. Our results shed new light on the protection of quantum discord by means of a quantum-reservoir engineering approach in quantum-information processing.

The dynamics of Bell nonlocality for three-qubit system in independent reservoirs

“…Recently, in the [36] An studied entanglement dynamics of two and three atoms in a common environment and found that the disentanglement of atoms can be largely delayed with the increase of the number of non-interacting atoms. Later, the similar idea is applied to the case of initial W state with independent reservoirs [37] (here each subsystem includes the interaction between n qubits and a zero-temperature reservoir called generalized amplitude damping model) for entanglement dynamics, which also has been suggested to protect pairwise entanglement [38][39][40], coherence [41][42][43][44], quantum discord [45] and reduce the entropic uncertainty lower bound [46].…”

Entropy squeezing for a generalized amplitude damping model

“…Recently, a generalized amplitude damping model composed of N noninteracting qubits coupled to a common reservoir is suggested to protect entanglement [26][27][28][29][30], coherence [31][32][33][34], quantum discord [35] and the entropic uncertainty lower bound [36]. In this paper, inspired by these studies we try to explore the squeezing property of the generalized amplitude damping model, which has not be seen for similar report up to now.…”