“Modular Quantum-to-Quantum Bernoulli Factory in an Integrated Photonic Processor” just published in Nature Photonics

Generating and manipulating randomness is essential for numerous information technology applications, and quantum mechanics has been shown to offer distinct advantages in this area. A notable model for randomness manipulation is the Bernoulli factory, which enables the controlled adjustment of the bias in Bernoulli random processes. Initially, this framework was explored entirely within a classical … Leggi tutto

Quantum Lab at the European Researchers’ Night 2024

The Quantum Lab group of Sapienza University organized an engaging didactic exposition on quantum mechanics and quantum technologies titled “Dire l’indicibile” as part of the European Researcher’s Night 2024, held at Città dell’Altra Economia last weekend in Roma (link: https://www.scienzainsieme.it/). The event aimed to explore the fascinating and often counterintuitive world of quantum mechanics, making … Leggi tutto

Sapienza Università di Roma, CNRS, VeriQloud : “Experimental verifiable multi-client blind quantum computing on a Qline architecture”

The exploitation of certification tools by end users represents a fundamental aspect of the development of quantum technologies as the hardware scales up beyond the regime of classical simulatability. Certifying quantum networks becomes even more crucial when the privacy of their users is exposed to malicious quantum nodes or servers as in the case of multi-client distributed blind quantum computing, where several clients delegate a joint private computation to remote quantum servers, e.g. federated quantum machine learning. In such protocols, security must be provided not only by keeping data hidden but also by verifying that the server is correctly performing the requested computation while minimizing the hardware assumptions on the employed devices. Notably, standard verification techniques fail in scenarios where the clients receive quantum states from untrusted sources such as, for example, in a recently demonstrated linear quantum network performing multi-client blind quantum computation. However, recent theoretical results provide techniques to verify blind quantum computations even in the case of untrusted state preparation. Equipped with such theoretical tools, in this work, we provide the first experimental implementation of a two-client verifiable blind quantum computing protocol in a distributed architecture. The obtained results represent novel perspectives for the verification of multi-tenant distributed quantum computation in large-scale networks.

The exploitation of certification tools by end users represents a fundamentalaspect of the development of quantum technologies as the hardware scales upbeyond the regime of classical simulatability. Certifying quantum networksbecomes even more crucial when the privacy of their users is exposed tomalicious quantum nodes or servers as in the case of multi-client distributedblind quantum computing, … Leggi tutto

Sapienza Università di Roma, LIN INL, IFN-CNR: “Variational quantum cloning machine on a photonic integrated interferometer”

A seminal task in quantum information theory is to realize a device able to produce copies of a generic input state with the highest possible output fidelity, thus realizing an optimal quantum cloning machine. Recently, the concept of variational quantum cloning was introduced: a quantum machine learning algorithm through which, by exploiting a classical feedback loop informed … Leggi tutto

Publication by UNIROMA1, CNR and CNRS “High-fidelity four-photon GHZ states on chip”

Mutually entangled multi-photon states are at the heart of all-optical quantum technologies. While impressive progress has 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 … Leggi tutto

Italian Quantum Weeks, 13-18 April 2024

Quantum Lab is pleased to announce the 2024 edition of the Italian Quantum Weeks (https://quantumweeks.it) exhibition “Speak the Unspeakable: A Journey into Quantum Mechanics” to be held at the Botanical Garden of Rome from 13 to 19 April. The event is organized in collaboration with the Department of Physics, the Museum of Physics and the … Leggi tutto

LIN INL: “Measuring relational information between quantum states, and applications”

The geometrical arrangement of a set of quantum states can be completely characterized using relational information only. This information is encoded in the pairwise state overlaps, as well as in Bargmann invariants of higher degree written as traces of products of density matrices. We describe how to measure Bargmann invariants using suitable generalizations of the … Leggi tutto