Realization of a high power optical trapping setup free from thermal lensing effects

Transmission of high power laser beams through partially absorbing materials modifies the light propagation via a thermally-induced effect known as thermal lensing. This may cause changes in the beam waist position and degrade the beam quality. Here we characterize the effect of thermal lensing associated with the different elements typically employed in an optical trapping setup for cold atoms experiments. We find that the only relevant thermal lens is represented by the $TeO_2$ crystal of the acousto-optic modulator exploited to adjust the laser power on the atomic sample. We then devise a simple and totally passive scheme that enables to realize an inexpensive optical trapping apparatus essentially free from thermal lensing effects

Fermionic statistics suppresses Fano resonances

Fano resonances and bound states with energy in the continuum are ubiquitous phenomena in different areas of physics. Observations, however, have been limited so far to single-particle processes. In this work we experimentally investigate the multi-particle case and observe Fano interference in a non-interacting two-particle Fano-Anderson model by considering propagation of two-photon states in engineered photonic lattices. We demonstrate that the quantum statistics of the particles, either bosonic or fermionic, strongly affects the decay process. Remarkably, we find that the Fano resonance, when two discrete levels are coupled to a continuum, is suppressed in the fermionic case

Accessibilità delle Web APP della DSI

Rendere un’applicazione web accessibile, oltre ad essere un dovere sociale, permette ad ogni utente di poter usufruire delle sue funzionalità in un modo più profittevole. Gli aspetti caratterizzanti l’accessibilità si dividono in due categorie principali: visibili e invisibili. I primi sono degli aspetti di cui l’utente ha un’esperienza diretta e sono ad esempio i colori utilizzati e il modo in cui sono realizzati gli elementi interattivi della pagina. I secondi, invece, corrispondono al modo in cui le pagine web sono codificate e possono essere analizzate da un lettore automatico. In questa trattazione saranno discusse entrambe le tipologie di aspetti e il focus sarà puntato sulla loro gestione nell’ambito dello sviluppo interno alla DSI, che ha tra i propri obiettivi la realizzazione di applicativi web a supporto delle attività amministrative dell’INFN

Double-degenerate Fermi mixtures of 6^6Li and 53^{53}Cr atoms

We report on the realization of a novel degenerate mixture of ultracold fermionic lithium and chromium atoms. Based on an all-optical approach, with an overall duty-cycle of about 13 seconds, we produce large and degenerate samples of more than 2$\times 10^5$ $^6$Li atoms and $10^5$ $^{53}$Cr atoms, with both species exhibiting normalized temperatures of about $T/T_{F}$=0.25. Additionally, through the exploitation of a crossed bichromatic optical dipole trap, we can controllably vary the density and degree of degeneracy of the two components almost independently, and widely tune the lithium-to-chromium density ratio. Our $^{6}$Li-$^{53}$Cr Fermi mixture opens the way to the investigation of a variety of exotic few- and many-body regimes of quantum matter, and it appears as an optimally-suited system to realize ultracold paramagnetic polar molecules, characterized by both electric and magnetic dipole moments. Ultimately, our strategy also provides an efficient pathway to produce dipolar Fermi gases, or spin-mixtures, of ultracold $^{53}$Cr atoms.Comment: 14 pages, 5 figure

Realization of a Cold Mixture of Fermionic Chromium and Lithium Atoms

We report on the production of a novel cold mixture of fermionic $^{53}$Cr and $^{6}$Li atoms delivered by two Zeeman-slowed atomic beams and collected within a magneto-optical trap (MOT). For lithium, we obtain clouds of up to $4 \,10^8$ atoms at temperatures of about $500\,\mu$K. A gray optical molasses stage allows us to decrease the gas temperature down to $45(5)\,\mu$K. For chromium, we obtain MOTs comprising up to $1.5\, 10^6$ atoms. The availability of magnetically trappable metastable $D$-states, from which $P$-state atoms can radiatively decay onto, enables to accumulate into the MOT quadrupole samples of up to $10^7$ $^{53}$Cr atoms. After repumping $D$-state atoms back into the cooling cycle, a final cooling stage decreases the chromium temperature down to $145(5)\,\mu$K. While the presence of a lithium MOT decreases the lifetime of magnetically trapped $^{53}$Cr atoms, we obtain, within a 5 seconds duty cycle, samples of about $4\, 10^6$ chromium and $1.5\,10^8$ lithium atoms. Our work provides a crucial step towards the production of degenerate Cr-Li Fermi mixtures.Comment: 14 pages, 8 figure

Un motore di Workflow per applicazioni web

Progettazione e sviluppo di un motore di workflow per processi gestionali informatizzati. Il termine workflow identifica il modello digitale di un processo di business attraverso la sua rappresentazione in forma di grafo orientato. Ogni nodo del grafo identifica un’azione ben definita, declinata in forma di passaggi decisionali, sottoprocessi e/o manipolazione dei dati di contesto, con l’obiettivo di supportare l’iter di un processo in maniera efficiente, misurabile e ripetibile. La definizione di un workflow implica sia aspetti statici che dinamici di un processo e ne modella il comportamento come un automa a stati finiti. Ogni collegamento dell’automa stabilisce un collegamento fra due attività, definendo condizioni di percorrenza formalizzate come funzioni booleane. Tali funzioni sono attivate nel momento in cui un attore o un sotto-processo conclude le attività previste dalla fase attuale e vuole transire alla successiva. Emerge, a questo punto, la necessità di un orchestratore che governi l’andamento del workflow, garantisca il rispetto dei vincoli imposti dal processo sottostante e punti alla “fase attuale” del flusso, permettendo di individuare i percorsi attivabili e le condizioni di percorribilità in funzione del contesto e degli attori

Green line hospital-territory study: A single-blind randomized clinical trial for evaluation of technological challenges of continuous wireless monitoring in internal medicine, preliminary results

Background: Wireless vital parameter continuous monitoring (WVPCM) after discharge is compared to regular monitoring to provide data on the clinical-economic impact of complex patients (CPs) discharged from Internal Medicine Units of Ospedale dei Castelli, Lazio. Primary outcome: Major complications (MC) reduction. Secondary outcomes: Patients who reached discharge criteria within the 7th day from admission; difference in MC incidence at the conclusion of the standard telemonitoring/clinical monitoring phase, 5 and 30 days after discharge; and conditions predisposing to MC occurrence. Methods: Open label randomized controlled trial with wearable wireless system that creates alerts on portable devices. Continuous glycemic monitoring is performed for patients with diabetes mellitus. Results: There were 110 patients enrolled (mean age: 76.2 years). Comorbidity: Cumulative Illness Rating Scale CIRS-CI (comorbidities index): 3.93, CIRS SI (severity index): 1.93. About 19% scored a BRASS (Blaylock Risk Assessment Screening Score) ≥20 indicating need for discharge planning requiring step-down care. Globally, 48% of patients in the control group had major complications (27 out of 56 patients), in contrast to 22% in the intervention group (12 out of 54 patients). Conclusions: Since WVPCM detects early complications during the post-discharge CPs monitoring, it increases safety and reduces inappropriate access to the Emergency Room, preventing avoidable re-hospitalizations

Il portale web degli acquisti INFN

L’oggetto di questo lavoro consiste nella descrizione delle applicazioni e dei servizi web progettati per il nuovo portale degli acquisti INFN. Sono descritti aspetti architetturali, metodologici ed organizzativi relativi al sistema nel suo insieme, rimandando a futuri lavori gli approfondimenti sulle singole componenti applicative