Tripartite Entanglement dynamics: the influence of intrinsic decoherence and decoherence channels

TL;DR

This paper investigates how intrinsic decoherence and various decoherence channels affect tripartite entanglement in a coupled qubit system modeled by an XXZ Heisenberg chain, revealing that magnetic field influences entanglement while decoherence generally suppresses it.

Contribution

It provides a comprehensive analysis of entanglement dynamics under multiple decoherence channels in a tripartite qubit system with intrinsic decoherence effects.

Findings

Magnetic field strength affects entanglement levels.

Intrinsic decoherence suppresses entanglement, with stronger decoherence causing greater suppression.

Dark periods of entanglement occur under non-Markovian dephasing for GHZ states.

Abstract

This study examines a system of three coupled qubits, focusing on entanglement measures in the presence of decoherence. It utilizes an XXZ Heisenberg chain with an external magnetic field and Dzyaloshinskii-Moriya interaction, considering intrinsic decoherence. The results reveal that only the magnetic field strength affects entanglement, while intrinsic decoherence suppresses it, with stronger decoherence leading to greater suppression. Various decoherence channels are analyzed, showing that the $I$-tangle typically decreases with increased decoherence, except for the generalized W state under phase damping channel, where only one qubit is affected. Interestingly, dark periods of $I$-tangle occur for the GHZ state under non-Markovian dephasing, and while steady-state entanglement disappears in this channel, it remains nonzero when starting from a mixture of GHZ and fully separable states. Additionally, under generalized amplitude damping channel, reduced bipartite states of a W state exhibit entanglement sudden death, while the steady-state $I$-tangle for the spectral decomposed state stays nonzero.