Strictly nonclassical behavior of a mesoscopic system

TL;DR

This paper experimentally demonstrates that a mesoscopic many-atom system exhibits strictly nonclassical behavior, challenging classical physics and highlighting quantum effects in large-scale systems without relying on quantum mechanics assumptions.

Contribution

The study applies a recently derived nonclassicality criterion to a large atomic system, showing nonclassical behavior without using quantum mechanics assumptions.

Findings

System with 2.6×10^5 atomic mass units shows nonclassical behavior.

Nonclassical effects influence an area in phase space 10^3 times larger than ħ.

Experimental evidence contradicts classical physics in a mesoscopic system.

Abstract

We experimentally demonstrate the strictly nonclassical behavior in a many-atom system using a recently derived criterion [E. Kot et al., Phys. Rev. Lett. 108, 233601 (2012)] that explicitly does not make use of quantum mechanics. We thereby show that the magnetic moment distribution measured by McConnell et al. [R. McConnell et al., Nature 519, 439 (2015)] in a system with a total mass of $2.6\times 10^5$ atomic mass units is inconsistent with classical physics. Notably, the strictly nonclassical behavior affects an area in phase space $10^3$ times larger than the Planck quantum $\hbar$.