Experimental learning of quantum states

The number of parameters describing a quantum state is well known to grow exponentially with the number of particles. This scaling clearly limits our ability to do tomography to systems with no more than a few qubits and has been used to argue against the universal validity of quantum mechanics itself. However, from a computational learning theory perspective, it … Continua a leggere

Photonic Simulation of Entanglement Growth and Engineering after a Spin Chain Quench published in Nature Communications

The time evolution of quantum many-body systems is one of the most important processes for benchmarking quantum simulators. The most curious feature of such dynamics is the growth of quantum entanglement to an amount proportional to the system size (volume law) even when interactions are local. This phenomenon has great ramifications for fundamental aspects, while … Continua a leggere

“Benchmarking integrated linear-optical architectures for quantum information processing” published in Scientific Reports

Photonic platforms represent a promising technology for the realization of several quantum communication protocols and for experiments of quantum simulation. Moreover, large-scale integrated interferometers have recently gained a relevant role in quantum computing, specifically with Boson Sampling devices and the race for quantum supremacy. Indeed, various linear optical schemes have been proposed for the implementation … Continua a leggere

“Learning an unknown transformation via a genetic approach” published in Scientific Reports

  Recent developments in integrated photonics technology are opening the way to the fabrication of complex linear optical interferometers. The application of this platform is ubiquitous in quantum information science, from quantum simulation to quantum metrology, including the quest for quantum supremacy via the boson sampling problem. Within these contexts, the capability to learn efficiently … Continua a leggere

“Entanglement of photons in their dual waveparticle nature” just published in Nature Communications

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 … Continua a leggere

“What Hong-Ou-Mandel interference says on two-photon frequency entanglement” published in Scientific Reports

Here we put forward some considerations on how Hong-Ou-Mandel interferometry provides signatures of frequency entanglement in the two-photon state produced by parametric down-conversion. We find that some quantitative information can be inferred in the limit of long-pulse pumping, while the short-pulse limit remains elusive. Marco Barbieri, Emanuele Roccia, Luca Mancino, Marco Sbroscia, Ilaria Gianani and … Continua a leggere

Optimal Measurements for Simultaneous Quantum Estimation of Multiple Phases” just published in Physical Review Letters with Editor Suggestion

Optimal Measurements for Simultaneous Quantum Estimation of Multiple Phases The conditions for simultaneous quantum estimation of multiple parameters are derived, a desired step forward for the design of future quantum imaging and metrology devices. Luca Pezzè, Mario A. Ciampini, Nicolò Spagnolo, Peter C. Humphreys, Animesh Datta, Ian A. Walmsley, Marco Barbieri, Fabio Sciarrino, and Augusto … Continua a leggere

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