# Entanglement of photons in their dual wave-particle nature

## TL;DR

This paper demonstrates the first deterministic generation of entanglement between photons' wave and particle properties, revealing new quantum correlations and potential for advanced quantum information applications.

## Contribution

The authors introduce and experimentally realize a scalable scheme to generate wave-particle entanglement of photons, a novel combination of fundamental quantum traits.

## Key findings

- Successfully generated wave-particle entanglement of two photons.
- Scheme can be extended to multiphoton wave-particle entanglement.
- Potential applications in quantum information protocols.

## Abstract

Wave-particle duality is the most fundamental description of the nature of a quantum object which behaves like a classical particle or wave depending on the measurement apparatus. On the other hand, entanglement represents nonclassical correlations of composite quantum systems, being also a key resource in quantum information. Despite the very recent observations of wave-particle superposition and entanglement, whether these two fundamental traits of quantum mechanics can emerge simultaneously remains an open issue. Here we introduce and experimentally realize a scheme that deterministically generates wave-particle entanglement of two photons. The elementary tool allowing this achievement is a scalable single-photon setup which can be in principle extended to generate multiphoton wave-particle entanglement. Our study reveals that photons can be entangled in their dual wave-particle nature and opens the way to potential applications in quantum information protocols exploiting the wave-particle degrees of freedom to encode qubits.