Unconventional Distance Scaling of Casimir-Polder Force between Atomic Arrays

TL;DR

This paper reveals that the Casimir-Polder force between atomic arrays exhibits an unconventional distance scaling due to their discrete structure, deviating from traditional universal decay behaviors, with implications for experimental measurement.

Contribution

It demonstrates a novel distance scaling behavior of dispersion forces in discrete atomic arrays, extending understanding beyond continuum models and proposing experimental verification.

Findings

Force crosses over from faster to slower decay with distance

Discrete lattice structure causes unconventional scaling

Predicted stronger deviations in Rydberg atomic arrays

Abstract

Conventionally, dispersion forces mediated by quantum vacuum fluctuations are known to exhibit universal distance scalings, with retardation typically leading to a faster decay of the interaction. Here, we show that this expectation fails for intrinsically discrete systems. Using the microscopic scattering approach, we study the Casimir-Polder interaction between two atomic arrays, and uncover an unconventional distance scaling in which the force crosses over from a faster decay at short separations to a slower decay in the retarded regime. This behavior originates from the discrete lattice structure and can be consistently understood within the scattering picture. Extending our analysis to Rydberg atomic arrays, we predict an even stronger deviation from conventional scaling and propose an experimentally feasible scheme for direct measurement. Our results provide a new platform for exploring dispersion forces beyond the continuum limit.