Heisenberg scaling of imaging resolution by coherent enhancement

TL;DR

This paper presents a quantum imaging technique that achieves Heisenberg-limited resolution while maintaining unambiguous detection, demonstrated by efficiently locating a target ion with high precision.

Contribution

The authors develop a method combining unambiguous detection with Heisenberg scaling, overcoming previous limitations in quantum-enhanced imaging.

Findings

Achieved Heisenberg scaling of imaging resolution.

Demonstrated efficient binary search for target localization.

Resolved a trapped ion within 0.3% of the excitation beam diameter.

Abstract

Classical imaging works by scattering photons from an object to be imaged, and achieves resolution scaling as $1/\sqrt{t}$, with $t$ the imaging time. By contrast, the laws of quantum mechanics allow one to utilize quantum coherence to obtain imaging resolution that can scale as quickly as $1/t$ -- the so-called "Heisenberg limit." However, ambiguities in the obtained signal often preclude taking full advantage of this quantum enhancement, while imaging techniques designed to be unambiguous often lose this optimal Heisenberg scaling. Here, we demonstrate an imaging technique which combines unambiguous detection of the target with Heisenberg scaling of the resolution. We also demonstrate a binary search algorithm which can efficiently locate a coherent target using the technique, resolving a target trapped ion to within 0.3% of the $1/e^2$ diameter of the excitation beam.