The dynamics of two entangled qubits exposed to classical noise: role of spatial and temporal noise correlations

TL;DR

This paper analyzes how classical noise with varying spatial and temporal correlations affects the entanglement decay of two qubits, providing insights into the influence of noise symmetry and correlation regimes.

Contribution

It introduces a comprehensive framework to study two-qubit entanglement decay under diverse classical noise correlations, considering spatial symmetries and different noise regimes.

Findings

Entanglement decay depends on noise correlation and symmetry.

The framework covers both Markovian and quasi-static noise regimes.

Insights into the role of noise symmetry in entanglement dynamics.

Abstract

We investigate the decay of two-qubit entanglement caused by the influence of classical noise. We consider the whole spectrum of cases ranging from independent to fully correlated noise affecting each qubit. We take into account different spatial symmetries of noises, and the regimes of noise autocorrelation time. The latter can be either much shorter than the characteristic qubit decoherence time (Markovian decoherence), or much longer (approaching the quasi-static bath limit). We express the entanglement of two-qubit states in terms of expectation values of spherical tensor operators which allows for transparent insight into the role of the symmetry of both the two-qubit state and the noise for entanglement dynamics.