Rise and fall of entanglement between two qubits in a non-Markovian bath

Roy S, Otto C, Menu R, Morigi G (2023)

Publication Type: Journal article

Publication year: 2023

Journal

Physical Review A American Physical Society

Book Volume: 108

Article Number: 032205

Journal Issue: 3

DOI: 10.1103/PhysRevA.108.032205

Abstract

We analyze the dynamics of quantum correlations between two qubits coupled to a linear chain of oscillators. The chain mediates interactions between the qubits and acts as a non-Markovian reservoir. The model is amenable to an analytical solution when the initial state of the chain is Gaussian. We study the dynamics of the qubits' concurrence starting from a separable state and assuming that the chain spectrum is gapped and the chain is initially in a thermal state. We identify three relevant regimes that depend on the strength of the qubit-chain coupling in relation to the spectral gap. These are (i) the weak-coupling regime, where the qubits are entangled at the asymptotics, (ii) the strong-coupling regime, where the concurrence can exhibit collapses followed by revivals with exponentially attenuated amplitude, and (iii) the thermal damping regime, where the concurrence rapidly vanishes due to the chain's thermal excitations. In all cases, if entanglement is generated, this occurs after a finite time has elapsed. This time scale depends exponentially on the qubits' distance and is determined by the spectral properties of the chain. Entanglement irreversible decay, on the other hand, is due to the dissipative effect induced by the coupling with the chain and is controlled by the coupling strength between the chain and qubits. This study unravels the basic mechanisms leading to entanglement in a non-Markovian bath and allows one to identify the key resources for realizing quantum coherent dynamics of open systems.

Additional Organisation(s)

Sonderforschungsbereich/Transregio 306/1: Quantenkooperativität von Licht und Materie - QuCoLiMa

Related research project(s)

Spatio-temporal structures in interacting spin systems (D02) TRR 306: Quantenkooperativität von Licht und Materie – QuCoLiMa Jan. 1, 2021 - Dec. 31, 2024

Involved external institutions

Universität des Saarlandes (UdS) DE Germany (DE)

How to cite

APA:

Roy, S., Otto, C., Menu, R., & Morigi, G. (2023). Rise and fall of entanglement between two qubits in a non-Markovian bath. Physical Review A, 108(3). https://doi.org/10.1103/PhysRevA.108.032205

MLA:

Roy, Sayan, et al. "Rise and fall of entanglement between two qubits in a non-Markovian bath." Physical Review A 108.3 (2023).

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