Quantum levitation of nanoparticles seen with ultracold neutrons

TL;DR

This paper demonstrates quantum levitation of nanoparticles using ultracold neutrons, revealing new effects at the intersection of fundamental interactions, and explaining anomalous neutron heating in traps.

Contribution

It introduces a novel explanation for nanoparticle levitation and its impact on neutron physics, linking surface forces with neutron lifetime measurement discrepancies.

Findings

Nanoparticles can be levitated in high-excited states by vdW/CP forces.

Interaction with nanoparticles accounts for unexplained neutron heating.

Potential implications for neutron lifetime experiment accuracy.

Abstract

Analyzing new experiments with ultracold neutrons (UCNs) we show that physical adsorption of nanoparticles/nano-droplets, levitating in high-excited states in a deep and broad potential well formed by van der Waals/Casimir-Polder (vdW/CP) forces results in new effects on a cross-road of fundamental interactions, neutron, surface and nanoparticle physics. Accounting for the interaction of UCNs with nanoparticles explains a recently discovered intriguing small heating of UCNs in traps. It might be relevant to the striking conflict of the neutron lifetime experiments with smallest reported uncertainties by adding false effects there.