Non-Markovianity in atom-surface dispersion forces

Abstract

We discuss the failure of the Markov approximation in the description of atom-surface fluctuationinduced 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.

Extended hydrodynamic description for nonequilibrium atom-surface interactions

“…This means that D H n ≈ D lc n reduces to the local Drude result D lc n reported in Ref. [46] and we obtain for the quantum frictional force experienced by an atom in the half-space geometry…”

“…This constraints the validity of the linear regime of the extended hydrodynamic model to frequencies ω r TM I (Γ, p)/(2 0 ρ eH (p)) (p λ −1 TF ), where ρ eH is the respective resistivity. Since the frictional force on atoms is dominated by frequencies ω p · v and for the planar geometry we have that p ∼ z −1 a [46], we conclude that the Ohmic response of the extended hydrodynamic model holds for velocities (see Fig. 4)…”

“…In the case of the moving microscopic object (ii), the origin of dissipation is different depending on whether the particle features some form of internal dissipation (as it is the case, e.g., for a metallic nanoparticle) or whether the damping is induced by the interaction with the electromagnetic field only, as it is the case in an atomic system. In this work, we only consider the latter case, where the radiation dressing, backaction and their interplay with the surface characterize the interaction between atom and surface [46]. If the internal dynamics is described in terms of a harmonic oscillator, the atomic power spectrum reads as (10) where α(ω, v) is the velocity-dependent atomic polarizability and θ(ω) is the Heaviside step function [46].…”

Towards detecting traces of non-contact quantum friction in the corrections of the accumulated geometric phase

“…The bosonic operators satisfy the commutation relation [â kω ,â † k ω ] = δ(k − k )δ(ω − ω ) creating and destroying "photons" in a wider meaning, since they are creation and destruction operators of composite states (field plus material). In particular, it has been shown that [50]…”

Non-Markovian transient Casimir-Polder force and population dynamics on excited- and ground-state atoms: Weak- and strong-coupling regimes in generally nonreciprocal environments

“…While there has been a large number of studies on the static CP force (see, e.g., [14]- [15] and references therein), studies of the transient CP force have been limited in scope (e.g., in [15] a Jaynes-Cummings, single mode field is assumed in the strong coupling case). And, there have been few studies of the non-Markovian CP force [16]. In this work, we consider the initial-value problem of introducing either an excited or a ground state atom into an environment at t = 0, which is a special case of the Dynamical Casimir Effect, which also encompasses photon generation from fast changes in geometry [17].…”