Quantum coherence and entanglement preservation in Markovian and non-Markovian dynamics via additional qubits

TL;DR

This paper explores how adding noninteracting qubits to reservoirs can preserve quantum coherence and entanglement in single and multiple qubit systems, effective in both Markovian and non-Markovian regimes.

Contribution

It introduces a scheme using additional qubits to protect quantum coherence and entanglement, with analytical expressions showing complete preservation as the number of added qubits increases.

Findings

Increased additional qubits lead to full preservation of coherence and entanglement.

Protection is effective in both Markovian and non-Markovian dynamics.

Entanglement protection occurs despite different reservoir behaviors.

Abstract

In this paper, we investigate preservation of quantum coherence of a single-qubit interacting with a zero-temperature thermal reservoir through the addition of noninteracting qubits in the reservoir. Moreover, we extend this scheme to preserve quantum entanglement between two and three distant qubits, each of which interacts with a dissipative reservoir independently. At the long time limit, we obtained analytical expressions for the coherence measure and the concurrence of two and three qubits in terms of the number of additional qubits. It is observed that, by increasing the number of additional qubits in each reservoir, the initial coherence and the respective entanglements are completely protected in both Markovian and non-Markovian regimes. Interestingly, the protection of entanglements occurs even under the individually different behaviors of the reservoirs.