Extended hydrodynamic description for nonequilibrium atom-surface interactions

Abstract

The dissipative properties of spatially nonlocal conductors are investigated in the context of quantum friction acting on an atom moving above a macroscopic body. The focus is on an extended version of the hydrodynamic model for the bulk material's electromagnetic response. It is shown that the standard hydrodynamic description is inadequate for evaluating the frictional force since it completely neglects Landau damping. The extended version of the model contains a frequencydependent compressibility factor for the Fermi liquid and qualitatively resolves this issue. For a quantitative assessment, these results are contrasted with those obtained for the more fundamental Boltzmann-Mermin model. Since the latter is technically involved, the simplicity of the extended hydrodynamic model allows for an easier analysis of the impact of nonlocality on quantum friction for other (planar) geometries. This is illustrated with an example involving a thin slab.

Wading through the void: Exploring quantum friction and nonequilibrium fluctuations

“…58 ). Mostly, we find algebraic dependencies of the form F ∝ −v δ /z κ a with δ and κ positive integers, but also non-algebraic forms have been obtained [120][121][122][123] . Such rather distinct predictions are not necessarily mutually exclusive.…”

“…This process is independent of electronic collisions at impurities, phonons or other electrons and is commonly referred to as Landau-damping 143 . In the case of quantum friction, Landau damping has been shown to lead to a significant enhancement of the force which can reach several orders of magnitude 42,120,122,123,144,145 . From the broader perspective, Landau damping can be one consequence of the spatially nonlocal description of the material (although not every nonlocal description necessarily includes Landau damping 25 ).…”

Quantum Thermodynamic Uncertainties in Nonequilibrium Systems from Robertson-Schrödinger Relations

“…The vacuum fluctuations of the massless field are scaleless, such that the Hadamard function has a rather long range effect at the order of the squared inverse distance from the source. Again, if additionally material bodies were present, the situation can be different in the vicinity of surfaces where, depending on the structure of the material [67,68], often higher-order inverse polynonmials [61,69,70] or even non-algebraic functions [71,72] for the distance-dependence occur.…”

Scattering theory of the screened Casimir interaction in electrolytes

“…Indeed, free electrons exhibit a nonlocal response that modifies the Casimir interaction between metallic plates [22][23][24][25][26]. The nonlocal response of metals has been recently considered in connection with quantum friction [27]. The unretarded van der Waals interaction between nonlocal half-spaces across a local medium has been derived in the context of metals [28] and electrolytes [21].…”