Estimation of physical quantities is at the core of most scientific research, and the use of quantum devices promises to enhance its performances. In real scenarios, it is fundamental to consider that resources are limited, and Bayesian adaptive estimation represents a powerful approach to efficiently allocate, during the estimation process, all the available resources. However, … Leggi tutto
High-dimensional biphoton states are promising resources for quantum applications, ranging from high-dimensional quantum communications to quantum imaging. A pivotal task is fully characterising these states, which is generally time-consuming and not scalable when projective measurement approaches are adopted. However, new advances in coincidence imaging technologies allow for overcoming these limitations by parallelising multiple measurements. Here, … Leggi tutto
Boson Sampling is a task that is conjectured to be computationally hard for a classical computer, but which can be efficiently solved by linear-optical interferometers with Fock state inputs. Significant advances have been reported in the last few years, with demonstrations of small- and medium-scale devices, as well as implementations of variants such as Gaussian … Leggi tutto
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 … Leggi tutto
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 … Leggi tutto
The violation of a Bell inequality is the paradigmatic example of device-independent quantum information: the nonclassicality of the data is certified without the knowledge of the functioning of devices. In practice, however, all Bell experiments rely on the precise understanding of the underlying physical mechanisms. Given that, it is natural to ask: Can one witness … Leggi tutto
UPDATE: New dates for the exhibition “Speak the unspeakable”. We look forward to meeting you from 11 to 13 April at the Museo Dell’Arte Classica at Sapienza Campus. Download the updated leaflet here Registration available here: https://sites.google.com/uniroma1.it/sapienzaquantumweeks The Italian Quantum Weeks brings together the national scientific community in quantum technologies intending to organize outreach events for students … Leggi tutto
Experimental engineering of high-dimensional quantum states is a crucial task for several quantum information protocols. However, a high degree of precision in the characterization of the noisy experimental apparatus is required to apply existing quantum-state engineering protocols. This is often lacking in practical scenarios, affecting the quality of the engineered states. We implement, experimentally, an … Leggi tutto
The Quantum Lab has published in the journal Science Bulletin a News and Views paper on the recent quantum computational advantage demonstration reported in Science from Prof. Jian-Wei Pan’s team in China. The race towards quantum computational advantage: milestone photonic experiment, Fabio Sciarrino, Nicolò Spagnolo, Science Bulletin 66, 637-639 (2021)
Quantum coherence marks a deviation from classical physics, and has been studied as a resource for metrology and quantum computation. Finding reliable and effective methods for assessing its presence is then highly desirable. Coherence witnesses rely on measuring observables whose outcomes can guarantee that a state is not diagonal in a known reference basis. Here, … Leggi tutto