Quantum Origin of Diffraction from Bright and Dark States

Abstract:Building upon the recently introduced particle interpretation of the double-slit experiment [Phys. Rev. Lett. 134, 133603 (2025)] which attributes interference phenomena to detector-coupled (bright) and detector-uncoupled (dark) states of light, we develop a continuous-mode extension of the bright- and dark-state framework. This extension addresses a conceptual distinction between interference and diffraction, that is, the transition from a finite set of discrete paths to a continuum of modes. Through the construction of a complete detector-oriented basis for single-slit diffraction, we demonstrate that the observed diffraction pattern arises from projection of the photon state onto a single bright mode by identifying the detectable and undetectable modes, with photons detected at intensity minima having zero probability, as they reside in modes spanning an infinite-dimensional dark subspace. Our approach thus provides a unified particle-based explanation of diffraction that connects quantum and classical wave optics, and reveals distinctive quantum signatures in higher-order correlations.

9 pages, 1 figure; Final version published in Phys. Rev. A

arXiv:2510.16329 [quant-ph]

(or arXiv:2510.16329v4 [quant-ph] for this version)

Phys. Rev. A 113, 052201 (2026)

https://doi.org/10.1103/w97w-4tm5 DOI(s) linking to related resources