196,812 research outputs found
Informational steady states and conditional entropy production in continuously monitored systems: The case of Gaussian systems
No full textThe act of measuring a system has profound consequences of dynamical and thermodynamic nature. In particular, the degree of irreversibility ensuing from a nonequilibrium process is strongly affected by measurements aimed at acquiring information on the state of a system of interest: the conditional and unconditional entropy production, which quantify the degree of irreversibility of the open system's dynamics, are related to each other by clearly interpreted informational quantities. Building on a recently proposed collisional model framework [G. T. Landi, M. Paternostro, and A. Belenchia, PRX Quantum 3, 010303 (2022)10.1103/PRXQuantum.3.010303], we investigate the case of continuous-variable information carriers prepared in Gaussian states and undergoing Gaussian processes. We build up a toolbox that fully characterizes the thermodynamics of continuously measured nonequilibrium Gaussian systems and processes, illustrating how the instruments hereby introduced provide key insight into recent experiments on mesoscopic quantum systems [M. Rossi, L. Mancino, G. T. Landi, M. Paternostro, A. Schliesser, and A. Belenchia, Phys. Rev. Lett. 125, 080601 (2020).</p
Dalla linguistica speaker free alla linguistica speaker based. Appunti a margine di una ricerca sul campo
No full textIn questo contributo gli autori riflettono sulla collocazione del parlante nelle indagine sociolinguistiche alla luce dell'esperienza maturata in seno all'Atlante Linguistico della Sicilia (ALS). Il progetto ha subito nel corso del suo farsi un riorientamento teorico dovuto alla constatazione che dalle inchieste non sono emersi solo numeri, percentuali di occorrenza e quant'altro, ma parlanti reali dotati di una loro fisionomia e di una loro storia. L'ALS si è dunque aperto ed ha accolto nuovi modelli di ricerca che pongono sempre più in primo piano il ruolo attivo del parlante. In questo nuovo contesto analitico, alle variabili classiche si affiancano (ma non si sostituiscono)altri costrutti teorici che muovono dall'uno (dal singolo paralnte9 al molteplice (gruppi, reti di comunicazione, comunità di pratica, comunità linguistica). Il punto centrale di una linguistica 'speaker-based' è il rapporto fra variazione intra- e inter-speaker. In questa direzione, gli autori pongono l'accento sulla multidimensionalità della variazione intra-individuale, che non può limitarsi ad essere isomorfa alla struttura sociale. Concetti quali stile e identità, vengono in questo senso presentati come altrettante chiavi per accedere al significato sociale della variazione linguistica
Parole per nascondere la cosa (nostra)
No full textBreve nota sul modo in cui la parola 'mafia' è stata usata da Cosa Nostra per nascondere la sua reale identità
Hybrid photonic technologies for quantum information tasks
No full textIn the last thirty years, Quantum Information has become an established research field, providing a unique framework to harness the properties of inherently quantum systems to process and transmit information in ways that surpass the capabilities of classical information processing. It has been shown how quantum-based approaches find several practical applications, such as quantum computing, simulation, metrology, and communication. In this context, thanks to continuous developments of photonic technologies, photon-based platforms have established themselves as an excellent experimental testbed for the demonstration and implementation of a wide range of Quantum Information Processing tasks. Within this framework, the main goal of the present Ph.D. thesis is to employ the toolbox of photon-based Quantum Information processing - together with the capabilities offered by a set of state-of-the-art photonic technologies related to photon generation, manipulation, and detection - to devise experimental platforms suitable for the demonstration of photon-based Quantum Information protocols. In this perspective, this work focused on developing a hybrid photonic architecture tailored for multiphoton Quantum Information experiments. I designed and assembled such a platform and characterized its underlying elements: Quantum Dot sources, time-to-spatial demultiplexing setups, and universal reconfigurable integrated photonic interferometers. This thesis's experimental results have been focused on the context of the characterization of multiphoton interference effects and the implementation of photon-based computational protocols. First, I experimentally investigated fully optical schemes suitable for the generation of polarization-based and orbital angular momentum-based entangled photon pairs via single photons emitted consecutively by a QD source. Then, given that the emergence of quantum interference effects in multiphoton scenarios is at the core of the concept of linear optical computing, I developed and validated, on one side, semi-device-independent techniques for characterizing multiphoton indistinguishability. On the other, I investigated the behavior of multiphoton interference effects in scenarios featuring partial distinguishability, where seemingly counterintuitive phenomena can arise. The last part of this Ph.D. thesis will be focused on the experimental realization of photon-based protocols related to quantum computing applications. I provided an experimental implementation of a hybrid quantum-classical technique that finds, via variational techniques, optimal linear optical circuits implementing a quantum cloning machine of dual-rail encoded qubits. Then, I considered a recently proposed routine for the manipulation of quantum randomness - the quantum-to-quantum Bernoulli Factory. I experimentally validated an architecture based on polarization-based encoding implementing such a protocol, exploiting the demultiplexed QD source interfaced with a fully in-bulk and modular interferometric setup. Finally, I employed the hybrid photonic architecture at its full capability to investigate a proof-of-principle photonic implementation of a so-called Adaptive Boson Sampling scheme, an approach that goes beyond the standard Boson Sampling paradigm via the addition of measurement-based adaptivity. Overall, the results reported here highlight the versatility of a hybrid photonic approach and may open the path toward increasingly complex demonstrations of photon-based platforms for Quantum Information tasks
Lingue e società nell'Italia contemporanea
No full textItalian, dialects, and immigrant languages are changing and overlapping within a political and social landscape marked by major transformations and problematic forms of communication. At the same time, stereotypes, longstanding prejudices, and new perspectives crowd the debate on languages, both inside and outside educational institutions. Drawing on a broad dataset—linguistic and demographic, quantitative and qualitative—this volume analyzes the complex relationship between languages and society in 21st-century Italy and its recent past. It employs a range of descriptive and analytical tools, some of which are examined in depth in relation to evolving linguistic models, as the field grapples with new processes and emerging areas of research
Cambiamento del modello contabile: esame degli effetti in una PMI
No full textQuali effetti produce il cambiamento del modello contabile in azienda? Quali sono le
ripercussioni a livello di controllo di gestione? Si analizza il caso di una PMI ponendo a confronto
il bilancio redatto in base alla normativa e ai principi contabili nazionali con quello redatto in
base all’«IFRS for SMEs» effettuando opportune considerazioni sulle risultanze riscontrate
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