Non-Markovianity in atom-surface dispersion forces

TL;DR

This paper demonstrates that neglecting non-Markovian effects in atom-surface interactions leads to significant inaccuracies, emphasizing the importance of considering long-time correlations for correct predictions of dispersion forces.

Contribution

It reveals the failure of the Markov approximation in describing atom-surface fluctuation-induced forces and highlights the crucial role of non-Markovian effects.

Findings

Markov approximation can mispredict force strength and dependencies

Long-time power-law tails influence dispersion force calculations

Non-Markovian effects are essential for accurate modeling

Abstract

We discuss the failure of the Markov approximation in the description of atom-surface fluctuation-induced interactions, both at equilibrium (Casimir-Polder forces) and out-of-equilibrium (quantum friction). Using general theoretical arguments, we show that the Markov approximation can lead to erroneous predictions of such phenomena with regard to both strength and functional dependencies on system parameters. Our findings highlight the importance of non-Markovian effects in dispersion interactions. In particular, we show that the long-time power-law tails of temporal correlations, and the corresponding low-frequency behavior, of two-time dipole correlations, neglected in the Markovian limit, dramatically affect the prediction of the force.