Loss-based Experimental Test of Bohr's Complementarity Principle with Single Neutral Atom

TL;DR

This paper experimentally tests Bohr's complementarity principle using a single neutral atom, demonstrating the relation between wave-like and particle-like behaviors and exploring conditions under which the principle appears violated.

Contribution

It provides a novel experimental verification of the complementarity relation with controlled imbalance losses, and offers a theoretical explanation within quantum mechanics.

Findings

Measured the complementarity relation $P^2+V^2\,\leq 1$ with single atoms.

Demonstrated that deliberate imbalance losses can violate the formal complementarity relation.

All results are consistent with quantum mechanics without wave-particle interference considerations.

Abstract

An experimental test of quantum complementarity principle based on single neutral atom trapped in a blue detuned bottle trap was here performed. A Ramsey interferometer was used to assess the wavelike behavior or particle-like behavior with second $\pi/2$-rotation on or off. The wavelike behavior or particle-like behavior is characterized by the visibility $V$ of the interference or the predictability $P$ of which-path information, respectively. The measured results fulfill the complementarity relation $P^2+V^2\leq1$. Imbalance losses were deliberately introduced to the stem and find the complementarity relation is then formally "violated." All the experimental results can be completely explained theoretically by quantum mechanics without considering the interference between wave and particle behaviors. This observation complements existing information concerning the BCP based on wave-particle duality of massive quantum.