High-fidelity generation of four-photon GHZ states on-chip

Mutually entangled multi-photon states are at the heart of all-optical quantum technologies. While impressive progresses have been reported in the generation of such quantum light states using free space apparatus, high-fidelity high-rate on-chip entanglement generation is crucial for future scalability. In this work, we use a bright quantum-dot based single-photon source to demonstrate the high … Continua a leggere

Orbital angular momentum based intra- and inter- particle entangled states generated via a quantum dot source

Engineering single-photon states endowed with Orbital Angular Momentum (OAM) is a powerful tool for quantum information photonic implementations. Indeed, thanks to its unbounded nature, OAM is suitable to encode qudits allowing a single carrier to transport a large amount of information. Nowadays, most of the experimental platforms use nonlinear crystals to generate single photons through … Continua a leggere

Twenty Years of Quantum State Teleportation at the Sapienza University in Rome

Quantum teleportation is one of the most striking consequences of quantum mechanics and is defined as the transmission and reconstruction of an unknown quantum state over arbitrary distances. This concept was introduced for the first time in 1993 by Charles Bennett and coworkers, it has then been experimentally demonstrated by several groups under different conditions … Continua a leggere

Experimental genuine tripartite nonlocality in a quantum triangle network has been published in PRX Quantum!

A joint paper between Sapienza, International Institute of Physics and Perimeter Institute on the observation of genuine nonlocality in a triangle network has been published in PRX Quantum!  Quantum networks are the center of many of the recent advances in quantum science, not only leading to the discovery of new properties in the foundations of quantum theory but … Continua a leggere

Quantifying n-photon indistinguishability with a cyclic integrated interferometer has been published in PRX!

A joint paper between IFN-CNR, CNRS and Sapienza on a new method for the quantification of n-photon indistinguishability has been published in PRX! We report on a universal method to measure the genuine indistinguishability of n-photons – a crucial parameter that determines the accuracy of optical quantum computing. Our approach relies on a low-depth cyclic … Continua a leggere

Daylight entanglement-based quantum key distribution with a quantum dot source

Entanglement-based quantum key distribution can enable secure communication in trusted node-free networks and over long distances. Although implementations exist both in fiber and in free space, the latter approach is often considered challenging due to environmental factors. Here, we implement a quantum communication protocol during daytime for the first time using a quantum dot source. … Continua a leggere

Quantum violation of local causality in an urban network using hybrid photonic technologies

Quantum networks play a crucial role in distributed quantum information processing, enabling the establishment of entanglement and quantum communication among distant nodes. Fundamentally, networks with independent sources allow for new forms of nonlocality, beyond the paradigmatic Bell’s theorem. Here we implement the simplest of such networks—the bilocality scenario—in an urban network connecting different buildings with … Continua a leggere