arXiv subjects

D. Reiche

Publications and source records attributed to D. Reiche.

4 recordsLinked to original sources

arXiv2026

Nonequilibrium Casimir-Polder Force: Motion-induced Thermal-like Effect

The Casimir-Polder force is analyzed when an atom is moving at a constant velocity relative to a collection of translationally invariant macroscopic bodies with generic shapes and compositions. The interaction is described within an approach that accurately treats the atom-field coupling and accounts for the backaction from the environment onto the moving particle. Previously overlooked aspects are uncovered and linked to the nonequilibrium and nonconservative nature of the interaction. Specifically, we examine a behavior that can be understood by characterizing the underlying physical processes in terms of a motional-induced effective temperature. This phenomenon shares similarities with the Fulling-Davies-Unruh effect, opening new perspectives for the understanding of nonequilibrium physics at work in the system.

quant-ph↗

arXiv2021

Electromagnetic Viscosity in Complex Structured Environments: From black-body to Quantum Friction

We investigate the nonconservative open-system dynamics of an atom in a generic complex structured electromagnetic environment at temperature $T$. In such systems, when the atom moves along a translation-invariant axis of the environment, a frictional force acts on the particle. The effective viscosity due to friction results from the nonequilibrium interaction with the fluctuating (quantum) electromagnetic field, which effectively sets a privileged reference frame. We study the impact of both quantum or thermal fluctuations on the interaction and highlight how they induce qualitatively different types of viscosity, i.e. quantum and black-body friction. To this end, we develop a self-consistent non-Markovian description that contains the latter as special cases. In particular, we show how the interplay between the nonequilibrium dynamics, the quantum and the thermal properties of the radiation, as well as the confinement of light at the vacuum-material interface is responsible for several interesting and intriguing features. Our analyses is relevant for a future experimental test of noncontact friction and the resulting electromagnetic viscosity.

quant-ph↗

arXiv2018

Quantum Rolling Friction

An atom moving in a vacuum at constant velocity and parallel to a surface experiences a frictional force induced by the dissipative interaction with the quantum fluctuations of the electromagnetic field. We show that the combination of nonequilibrium dynamics, anomalous Doppler effect and spin-momentum locking of light mediates an intriguing interplay between the atom's translational and rotational motion. In turn, this deeply affects the drag force in a way that is reminiscent of classical rolling friction. Our fully non-Markovian and nonequilibrium description reveals counterintuitive features characterizing the atom's velocity-dependent rotational dynamics. These results prompt interesting directions for tuning the interaction and for investigating nonequilibrium dynamics as well as the properties of confined light.

quant-ph↗

arXiv2017

Spatial dispersion in atom-surface quantum friction

We investigate the influence of spatial dispersion on atom-surface quantum friction. We show that for atom-surface separations shorter than the carrier's mean free path within the material, the frictional force can be several orders of magnitude larger than that predicted by local optics. In addition, when taking into account spatial dispersion effects, we show that the commonly used local thermal equilibrium approximation underestimates by approximately 95% the drag force, obtained by employing the recently reported nonequilibrium fluctuation-dissipation relation for quantum friction. Unlike the treatment based on local optics, spatial dispersion in conjunction with corrections to local thermal equilibrium not only change the magnitude but also the distance scaling of quantum friction.

quant-ph↗