Il Colle di Galileo <p><em>Il Colle di Galileo</em>&nbsp;is the "display window" for the initiatives promoted by the agreement "Il Colle di Galileo – Galileo's Hill" among the University of Florence, CNR, INAF and INFN.<br>It publishes articles, by invitation only, both in Italian and in English in order to describe the main activities in Physics research taking place in several Institutions in the Arcetri area. Namely: Department of Physics and Astronomy (UNIFI), Galileo Galilei Institute for Theoretical Physics (INFN and UNIFI), National Institute of Optics (CNR) and Astrophysical Observatory of Arcetri. These include scientific reports of events like international conferences and workshops and highlights on the main results obtained by the research of "Galileo's Hill" institutes.</p> Firenze University Press en-US Il Colle di Galileo 2281-7727 <p>Authors retain the copyright and grant the journal right of first publication with the work simultaneously licensed under a <strong>Creative Commons Attribution 4.0 International Public License (<a href="">CC-BY-4.0</a>)</strong>&nbsp;that allows others to share the work with an acknowledgment of the work's authorship and initial publication.</p> <p><a href="" rel="license"><img src="" alt="Creative Commons License"></a><br>This work is licensed under a <a href="" rel="license">Creative Commons Attribution 4.0 International License</a></p> Cortona Young (online conference) <p class="p1">The e-Conference “Cortona Young”, hosted by the GGI on May 27-29, 2020, was set up as a response to the postponement of the 2020 edition of the Italian National Meetings “New Frontiers in Theoretical Physics - Convegno di Fisica Teorica di Cortona”, due to the COVID-19 pandemic.&nbsp;The conference was primarily addressed to young researchers, graduate students and postdocs connected with the Italian community of theoretical high energy physics. The aim was to give visibility to their most recent results in spite of the difficult situation for scientific exchanges. The program consisted of 12 live web-seminars, selected among over 50 applications, and of 24 video posters, made&nbsp;available through the GGI YouTube channel. The selected topics&nbsp;covered many different aspects of theoretical high energy physics, ranging from field and string theory to statistical mechanics, phenomenology and astroparticle physics. There were over 140 online participants, who were able to enter different virtual rooms for more focused discussion sessions. A special committee selected the best seminar, whose speaker was awarded a plenary talk in the next live edition of the Cortona meeting.</p> AAVV AAVV Copyright (c) 2021 2021-03-17 2021-03-17 10 1 5 7 10.36253/cdg-12711 “New Frontiers in the Search for Dark Matter” <p class="p1">The workshop brought together world experts working on the origin of dark matter, one of the most urgent questions in fundamental physics. For seven weeks, scientists explored new theoretical avenues as well as novel detection strategies. The event benefited from the presence of Simons Fellows, who led discussions on well-motivated theories and the status of current fast-moving experimental searches.</p> AAVV AAVV Copyright (c) 2021 2021-03-17 2021-03-17 10 1 9 13 10.36253/cdg-12712 Breakdown of Ergodicity in Isolated Quantum Systems: From Glassiness to Localization <p class="p1">We report on a workshop, held at GGI, in which researchers from several universities and research centers around the world met to discuss recent breakthroughs in our understanding of the approach to thermal equilibrium of quantum systems. The discussion spanned from the fundamental problems concerning the interplay of the foundations of thermodynamics and quantum mechanics, to the implications for quantum technologies, in particular for quantum computing.</p> AAVV AAVV Copyright (c) 2021 2021-03-17 2021-03-17 10 1 15 17 10.36253/cdg-12713 Polarization: a diagnostic tool for protoplanetary disks <p class="p1">The rotating disk of gas and dust observed around young stars is the birthplace of planets. The study of its properties is fundamental to understand the formation and evolution of nascent worlds. Polarimetric data obtained with the Atacama Large Millimeter/Submillimeter Array (ALMA) are a new powerful tool to investigate the properties of the dust and magnetic structure in these systems.</p> Francesca Bacciotti Copyright (c) 2021 Francesca Bacciotti 2021-03-17 2021-03-17 10 1 19 24 10.36253/cdg-12714 Stellar age revealed by chemical composition <p class="p1">High-resolution spectroscopic surveys provide an extraordinary dataset on the processes of the formation and evolution of our galaxy, in which the determination of the ages of individual stars plays a major role. We present here a method for measuring stellar ages based on the carbon/nitrogen abundance ratio in stellar atmospheres. We apply this relationship to the disc of the Milky Way, finding a clear age difference between the thin and thick discs of our galaxy.</p> Laura Magrini Giada Casali Copyright (c) 2021 Laura Magrini, Giada Casali 2021-03-17 2021-03-17 10 1 25 29 10.36253/cdg-12715 The last frontier of natural guide star adaptive optics <p class="p1">Adaptive optics is finding increasingly relevant applications in ground-based optical and infrared astronomy and will be the key technique for the next generation of telescopes. The technology group at INAF-Osservatorio Astrofisico di Arcetri has recently installed a frontier instrument on the Large Binocular Telescope and has obtained the first astrophysical data confirming its innovative performance.</p> Enrico Pinna Copyright (c) 2021 Enrico Pinna 2021-03-17 2021-03-17 10 1 31 36 10.36253/cdg-12716 A Fourier transform microspectrometer in a droplet <p class="p1">An experiment at the National Institute of Optics (INO) of the CNR has shown the possibility of carrying out spectrochemical analysis of a material simply by exploiting the evaporation of a liquid drop on the tip of an optical fiber. Endowed with a proper data analysis procedure, this simple optofluidic system is equivalent to a miniaturized Fourier transform spectrometer, capable of operating automatically and at an extremely low production cost.</p> Pietro Malara Copyright (c) 2021 Pietro Malara 2021-03-17 2021-03-17 10 1 37 41 10.36253/cdg-12717 A quantum cryptography system used to encrypt the Italian Prime Minister’s videocall at ESOF2020 <p class="p1">During the closing ceremony of the EuroScience Open Forum (ESOF2020), held on 6 September in Trieste, Prime Minister Giuseppe Conte took part in a public demonstration of a quantum cryptography protocol, carried out by the Quantum Communications group of the National Institute of Optics of Florence. The demonstration exploited the transmission of quantum states through the LightNet fiber optic network.</p> Ilaria Vagniluca Nicola Biagi Davide Bacco Alessandro Zavatta Copyright (c) 2021 Ilaria Vagniluca, Nicola Biagi, Davide Bacco, Alessandro Zavatta 2021-03-17 2021-03-17 10 1 43 47 10.36253/cdg-12718