Entangled Fock states for Robust Quantum Optical Metrology, Imaging, and Sensing

TL;DR

This paper introduces a new class of path-entangled Fock states that are highly resistant to loss, enhancing quantum metrology, imaging, and sensing by maintaining coherence and super-resolution capabilities even in lossy environments.

Contribution

It proposes and models a novel class of entangled photon states that outperform N00N states in lossy conditions, improving robustness in quantum optical applications.

Findings

Entangled Fock states show greater resilience to loss than N00N states.

These states achieve higher visibility under environmental decoherence.

Detection schemes based on these states enhance super-resolution imaging.

Abstract

We propose a class of path-entangled photon Fock states for robust quantum optical metrology, imaging, and sensing in the presence of loss. We model propagation loss with beam-splitters and derive a reduced density matrix formalism from which we examine how photon loss affects coherence. It is shown that particular entangled number states, which contain a special superposition of photons in both arms of a Mach-Zehnder interferometer, are resilient to environmental decoherence. We demonstrate an order of magnitude greater visibility with loss, than possible with N00N states. We also show that the effectiveness of a detection scheme is related to super-resolution visibility.