Dipartimento di Fisica Sapienza Università di Roma
The image on the cover for Advanced Photonics Volume 1, Issue 4, provides a pictorial view of the hybrid two-photon entangled state. Quantum entanglement is present between the polarization of a first photon (bottom) and the vector vortex state of a second photon (top). The second photon has been transmitted through an air-core fiber and … Continua a leggere
Entanglement distribution between distant parties is one of the most important and challenging tasks in quantum communication. Distribution of photonic entangled states using optical fiber links is a fundamental building block toward quantum networks. Among the different degrees of freedom, orbital angular momentum (OAM) is one of the most promising due to its natural capability … Continua a leggere
Instrumental variables allow the estimationof cause and effect relations even in pres-ence of unobserved latent factors, thus provid-ing a powerful tool for any science whereincausal inference plays an important role.More recently, the instrumental scenario hasalso attracted increasing attention in quantumphysics, since it is related to the seminal Bell’stheorem and in fact allows the detection ofeven … Continua a leggere
Quantum tomography is currently the mainly employed method to characterize a quantum system and therefore plays a fundamental role when trying to characterize the action of a particular channel. Nonetheless, quantum tomography works on the premise of a full characterization and description of the devices preparing the quantum state and realizing the measurements. Such an … Continua a leggere
Boson sampling is a computational problem that has recently been proposed as a candidate to obtain an unequivocal quantum computational advantage. The problem consists in sampling from the output distribution of indistinguishable bosons in a linear interferometer. There is strong evidence that such an experiment is hard to classically simulate, but it is naturally solved … Continua a leggere
Quantum Information and Measurement (QIM) – V: Quantum Technologies Rome, 4-6 April 2019 Details at www.quantumlab.it/qim2019/ All accepted papers will be published and indexed as Conference Proceedings in OSA Technical Digest. Program Chairs Fabio Sciarrino, University of Rome La Sapienza David Lucas, University of Oxford Chairs Ian Walmsley (OSA President), UCL Irfan Siddiqi, University of … Continua a leggere
Published on March 29 in Science Advances, experimentally demonstrates for the first time that it is possible to efficiently describe a quantum state, using the tools of computational learning theory. In fact it is known that in general the description of a quantum state requires a number of parameters that grows exponentially with the number … Continua a leggere
Inferring causal relations from empirical data is a central task in any scientific inquiry. To that aim, a mathematical theory of causality has been developed, not only stating under which conditions such inference becomes possible but also offering a formal framework to reason about cause and effect within quantum theory. This perspective article provides an … Continua a leggere
Classical machine learning algorithms can provide insights on high-dimensional processes that are hardly accessible with conventional approaches. As a notable example, t-distributed Stochastic Neighbor Embedding (t-SNE) represents the state of the art for visualization of data sets of large dimensionality. An interesting question is then if this algorithm can provide useful information also in quantum … Continua a leggere
Multiparameter estimation is a general problem that aims at measuring unknown physical quantities, obtaining high precision in the process. In this context, the adoption of quantum resources promises a substantial boost in achievable performances with respect to the classical case. However, several open problems remain to be addressed in the multiparameter scenario. A crucial requirement … Continua a leggere