Unconventional distance scaling of Casimir-Polder force between atomic arrays
Phys. Rev. A 113, 062813 – Published 22 June, 2026
DOI: https://doi.org/10.1103/fwk9-ptxy
Abstract
Conventionally, dispersion forces mediated by quantum vacuum fluctuations are known to exhibit universal distance scaling, 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 platform for exploring dispersion forces beyond the continuum limit.
