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

Reconfigurable continuously-coupled 3D photonic circuit for Boson Sampling experiments

Boson Sampling is a computational paradigm representing one of the most viable and pursued approaches to demonstrate the regime of quantum advantage. Recent results have shown significant technological leaps in single-photon generation and detection, leading to progressively larger instances of Boson Sampling experiments in different photonic systems. However, a crucial requirement for a fully-fledged platform … Continua a leggere

Certification of Gaussian Boson Sampling via graph theory

Gaussian Boson Sampling is a non-universal model for quantum computing inspired by the original formulation of the Boson Sampling problem. Nowadays, it represents a paradigmatic quantum platform to reach the quantum advantage regime in a specific computational model. Indeed, thanks to the implementation in photonics-based processors, the latest Gaussian Boson Sampling experiments have reached a … Continua a leggere

The potential and global outlook of integrated photonics for quantum technologies

Integrated quantum photonics uses classical integrated photonic technologies and devices for quantum applications. As in classical photonics, chip-scale integration has become critical for scaling up and translating laboratory demonstrators to real-life technologies. Integrated quantum photonics efforts are centred around the development of quantum photonic integrated circuits, which can be monolithically, hybrid or heterogeneously integrated. In … Continua a leggere

Experimental test of quantum causal influences

Since Bell’s theorem, it is known that local realism fails to explain quantum phenomena. Indeed, Bell inequality violations manifestly show the incompatibility of quantum theory with classical notions of cause and effect. As recently discovered, however, the instrumental scenario –a pivotal tool in causal inference– allows for nonclassicality signatures going beyond this paradigm. Indeed, if … Continua a leggere

Quantum walks of two correlated photons in a 2D synthetic lattice

Quantum walks represent paradigmatic quantum evolutions, enabling powerful applications in the context of topological physics and quantum computation. They have been implemented in diverse photonic architectures, but the realization of two-particle dynamics on a multidimensional lattice has hitherto been limited to continuous-time evolutions. To fully exploit the computational capabilities of quantum interference it is crucial … Continua a leggere