QTeQ strikes Physical Review in first half of 2020

Despite the unusual circumstances, QTeQ has published several works in Physical Review in the first half of 2020, highlighting QTeQ’s top-quality research and fruitful collaborative environment: 3 Phys. Rev. Lett. (summarized below), 2 Phys. Rev. Research, 1 Phys. Rev. B and 2 Phys. Rev. E. Well done!!

In the first of the 2020’s QTeQ’s PRLs, “Machine learning-based classification of vector vortex beams” Phys. Rev. Lett. 124, 160401 (2020), done in collaboration with Fabio Sciarrino’s group at Sapienza Università di Roma, QTeQ’s endeavors have focused on the machine learning side, in particular, in the use of convolutional neural networks and principal component analysis for the classification of specific and complex polarization patterns. This work demonstrates the significant advantages resulting from the use of machine learning-based protocols for the construction and characterization of high-dimensional resources for quantum protocols.

The second PRL in the list goes to “Quantum State Engineering by Shortcuts to Adiabaticity in Interacting Spin-Boson Systems” Phys. Rev. Lett. 124, 180401 (2020), a QTeQ-made work where shortcuts-to-adiabaticity protocols have been demonstrated to be very well suited to generate a breadth of quantum states with very high fidelities, while allowing for a reduced evolution time for their preparation and thus naturally robust against potential decoherence processes. Thanks to the ubiquity of the considered Jaynes-Cummings interaction, such protocols can be relevant in several experimental platforms, where interesting quantum states could be realize, such as Fock states, cat-like superposition thereof, and states akin to photon-added and subtracted.

The third PRL goes to a novel phenomenon blending nonequilibrium dynamics and open quantum systems, “Universal anti-Kibble-Zurek scaling in fully-connected systems” Phys. Rev. Lett. 124, 230602 (2020), done in collaboration with Andrea Smirne (Milan) and Susana F. Huelga and Martin B. Plenio (Ulm). Although a driven critical system features Kibble-Zurek scaling laws, those are typically sensitive to the unavoidable system-environment interaction leading to an anti-Kibble-Zurek effect, namely, the slower the quench, the more nonequilibrium excitations are created. In this work we have shown that, even when the standard (isolated) scaling laws break down due to the open nature of the dynamics, there is an anti-Kibble-Zurek scaling which depends solely on the equilibrium critical exponents of the phase transition.

Keep up the momentum!!

Congratulations to Dr. Innocenti!!

QTeQ is proud of their own Luca Innocenti, who successfully defended his PhD thesis today 12th of June 2020. Luca’s work, which blended theory and experiments addressing the use of machine learning in quantum physics, was assessed by Gabriele (internal examiner) and Prof. Marco Barbieri from University Roma Tre (Italy).

Well done Luca!!

New paper in Nature Communications by Alessio and co-workers!

Congratulations to Alessio and co-workers on their recently accepted paper in the prestigious Nature Communications (https://www.nature.com/articles/s41467-020-16013-1) on quantum clocks and the temporal localisability of events in the presence of gravitating quantum systems!!

In this recent work, with lead author Dr Esteban Castro-Ruiz, a team of physicists led by Professor Caslav Brukner from the University of Vienna and the Institute for Quantum Optics and Quantum Information (IQOQI) Vienna explored the temporal localisability of events when quantum systems influence space-time according to Einstein’s general relativity. Dr Alessio Belenchia, from Queen’s University Belfast, is among the authors of this new work.

The study develops a framework to operationally define events and their localisation with respect to a quantum clock reference frame, also in the presence of gravitating quantum systems. The major results are that the time localisability of events becomes relative, depending on the reference frame, and that for each event there exists always a (quantum) clock according to which that event occurs at a sharp, precise time. This is useful because, using this clock as a reference, the time evolution of quantum systems still can be described similarly as in the ordinary situations where all events are localised in time.