Robustness of Highly Entangled Multi-Qubit States Under Decoherence

TL;DR

This paper studies how entanglement in highly entangled multi-qubit states decays under decoherence, identifying the most robust states for small systems and specific channels, with implications for quantum information stability.

Contribution

It characterizes the robustness of multi-qubit entangled states under decoherence and identifies states with maximal entanglement resilience for small systems.

Findings

Certain initial states exhibit maximal robustness against decoherence.

Robustness varies with different decoherence channels.

States equivalent to GHZ are less robust than some other entangled states.

Abstract

We investigate the decay of entanglement, due to decoherence, of multi-qubit systems that are initially prepared in highly (in some cases maximally) entangled states. We assume that during the decoherence processes each qubit of the system interacts with its own, independent environment. We determine, for systems with a small number of qubits and for various decoherence channels, the initial states exhibiting the most robust entanglement. We also consider a restricted version of this robustness optimization problem, only involving states equivalent under local unitary transformations to the |GHZ> state.