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Las novelas cortas de Luis Mateo Díez: memoria, imaginación y palabra en las “Fábulas del sentimiento”
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Greta Thunberg: la ricezione del discorso alle Nazioni unite. Analisi di articoli giornalistici in lingua italiana e russa
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Development of a new experimental setup for the measurement of electron electric dipole moment
Get PDFAbstract in italiano (la versione originale è già in inglese):
Il progresso della ricerca scientifica ha portato alla scoperta di fenomeni quali l’asimmetria materia - antimateria,
nota come problema della bariogenesi, o l’origine microscopica della materia oscura, che hanno reso evidente
l’incompletezza del Modello Standard. Al momento tuttavia esso costituisce la teoria più valida per la comprensione
di larga parte dei fenomeni fisici (gravità esclusa), capace di prevedere con assoluta precisione una vastissima
quantità di eventi. Uno dei maggiori campi di indagine della fisica dei giorni nostri è dunque legato al tentativo
di superare il Modello Standard, cercando evidenze sperimentali che indichino la strada verso la scoperta
di nuova fisica. Un notevole impedimento è costituito dalla scala di energie necessarie in questi studi,
spesso oltre la portata di LHC, attualmente il più potente acceleratore di particelle a nostra disposizione.
Con le recenti innovazioni, un aiuto importante potrebbe derivare quindi da misure di precisione a bassa energia.
In tale ottica si pone la ricerca per la misura del momento di dipolo elettrico (EDM) delle particelle elementari,
come l’elettrone, in quanto una simile scoperta costituirebbe una prova diretta della violazione delle simmetrie per
inversione temporale (T) e parità (P) su scale non previste dallo Standard Model. Una misura di tal genere ancora
non è stata effettuata a causa dell’estrema sensibilità necessaria, tuttavia grandi progressi sono stati compiuti
raggiungendo precisioni assai elevate. Questa tesi si propone di evidenziare l’importanza teorica di una misura
dell’EDM delle particelle elementari con particolare attenzione al caso dell’elettrone, illustrando poi alcuni dei
più rilevanti approcci sperimentali utilizzati. In particolare, si porrà l’attenzione su una tecnica non
spettroscopica che prevede l’utilizzo di molecole biatomiche polari intrappolate in una matrice di paraidrogeno;
a tal proposito, verranno infine presentati i risultati di alcuni studi riguardanti porzioni del setup sperimentale,
effettuati presso i Laboratori Nazionali di Legnaro dell’INFN.
Abstract in inglese:
The progress of scientific research has led to the discovery of phenomena such as matter - antimatter
asymmetry, known as the problem of baryogenesis, or the microscopic origin of dark matter, which has
revealed the incompleteness of the Standard Model. Currently, it constitutes the most valid theory
in order to understand most of the physical phenomena (excluding gravity), capable of predicting
with absolute precision a vast quantity of events. One of the greatest fields of investigation of physics
at the present time is therefore related to the attempt to find a way around the Standard Model,
seeking experimental evidence that could indicate the road towards the discovery of new physics.
A significant obstacle is constituted by the scale of energies required in these studies, often beyond
the realms of LHC, currently the most powerful particle accelerator available to us. With recent
innovations, an important contribution could therefore stem from low-energy precision measurements.
In this perspective, the search for measurement of the electric dipole moment (EDM) of elementary
particles, as the electron, is proposed, as a similar discovery would constitute direct proof of the
violation of symmetries for time reversal (T) and parity (P) on a scale not envisaged by the Standard
Model. A measurement of this kind has still not been made due to the extreme sensitivity necessary,
however good progress has been made in achieving fairly high levels of precision. This thesis aims
to highlight the theoretical importance of a measurement of the EDM of elementary particles with
particular attention to the case of the electron, then illustrating some of the most relevant experimental
approaches used. In particular, the focus will be on a non-spectroscopic technique that involves the
use of polar diatomic molecules trapped in a parahydrogen matrix; in this regard, the results of a
number of studies concerning portions of the experimental setup will finally be presented, performed
at the INFN National Laboratories, based in Legnaro, Padua, Italy
Optimal quantum gates for Rydberg atoms quantum computer
No full textArrays of identical neutral atoms trapped in optical tweezers are a promising candidate for use in quantum computing. These platforms are highly scalable to large numbers of qubits and neutral atoms boost several attractive features as long coherence times and the possibility to be entangled via strong dipole-dipole interactions by driving them to highly excited Rydberg states.
The Thesis work is developed inside the framework of the QRydDemo project, whose aim in the next few years is to realize a neutral atom quantum processor with several hundred qubits. The smallest building blocks for the quantum computer are one and two-qubit gates: to entangle two atoms in the quantum register, a controlled-phase (CZ) gate will be implemented by shining fine-tuned laser pulses onto them. In this work, after giving a theoretical description of the Hamiltonian of two neutral atoms in the quantum register, a numerical simulation of this system is exploited to reproduce the behavior of the two-qubit CZ gate. Realistic effects are taken into account as finite temperature, imperfect Rydberg blockade, or decay out of the Rydberg state. A protocol with constant pulses is analyzed and its optimal parameters are found through classical optimizers. Then, time-dependent pulses are introduced and the optimal pulses are found through the optimal control algorithm dCRAB in an open-loop optimization. For the experimental realization of the gate, this analysis is of pivotal importance to know in which aspect more effort has to be put to maximize the experimental precision of the operation and thus improving the performance of the whole devic