Elenco Argomenti di Tesi in Physics - List of available master thesis

Acoustic wave propagation in granular media

Titolo Tesi:
Acoustic wave propagation in granular media

Thesis Supervisors:
Int.:
Ext.: [ ]

Brief Description:

Granular materials are frequently utilized to mitigate mechanical vibrations in the development of mechanical devices and machines. Despite their widespread applicability, a thorough comprehension of the exact roles played by particle arrangements and force chains in this process still eludes us. The objective of the thesis is to investigate the velocity of acoustic waves in granular assemblies. The research will be conducted through molecular dynamic simulations, supplemented by analytical calculations based on the approximations of effective medium theory.

Preparatory Courses:

Statistical Mechanics, Modeling of Complex Systems

Acoustic and inertial sensing with optical fiber interferometers

Titolo Tesi:
Acoustic and inertial sensing with optical fiber interferometers

Thesis Supervisors:
Int.:
Ext.: [ Dr. Gianluca Gagliardi, Dr. Saverio Avino, Dr. Pietro Malara, Consiglio Nazionale delle Ricerche, Istituto Nazionale di Ottica (CNR-INO), Pozzuoli (IT) ]

Brief Description:

Novel optronic systems aimed at local and distributed sensing of strain, vibrations, deformations, accelerations and rotations can be developed harnessing the intrinsic properties of optical fibers, being miniaturized, lightweight, cheap, insensitive to electromagnetic interference and ideal for integration in structures and materials. Also, guided propagation and negligible losses of optical fibers make them ideal platforms to realize such optronic devices. The research in this direction will be conducted through different experimental settings: 1) optical fiber architectures comprising fiber-optic resonators and exotic grating structures also combined with plasmonic nanostructures; 2) fiber-optic closed-ring interferometers built within highly thermally and mechanically insulated systems. Direct applications include chemical analysis for environmental and biological monitoring and acoustic sensing, geophysical studies, seismic monitoring and navigation, while sensing the smallest modifications of the fiber guiding properties can be also used to indirectly measure the intensity of an electric field, the irradiance of ionizing radiation or rheological properties of fluids.

Preparatory Courses:

Introduction to Optical Sensing Techniques, Laser Spectroscopy

Optical whispering gallery mode microresonators

Titolo Tesi:
Optical whispering gallery mode microresonators

Thesis Supervisors:
Int.:
Ext.: [ Dr. Gianluca Gagliardi, Dr. Antonio Giorgini, Dr. Davide D’Ambrosio, Consiglio Nazionale delle Ricerche, Istituto Nazionale di Ottica (CNR-INO), Pozzuoli (IT) ]

Brief Description:

Over the last few decades, optical WGM resonators allowed enormous progresses in a number of different fields of fundamental and applied science. At small length scales, from microns to millimeters, dielectric micro-sphere and microtoroids showed impressive Q-factors which were exploited for bio-chemical sensing, lasers and nonlinear optics experiments. In our group, we explored the idea of liquid optical microcavities, i.e. a self-sustained drop of liquid where light can be trapped and resonate with very low loss, demonstrating, for the first time, the feasibility of droplets as passive sensors. Free-space light excitation of whispering-gallery modes and laser frequency locking on resonant modes is achieved, recording Q-factors ranging from 105 to 107 in the near-infrared and visible spectral regions. Liquid cavities are unique environments to investigate light–matter interaction and optomechanics. Also, custom-built solid silica microspheres can be immersed in aqueous solutions and excited in a free-space light configuration as a platform for biosensing applications. Nanostructures and nanoparticles can be dispersed in the liquid medium and detected as a result of the interaction with the whispering gallery mode, thereby opening the way to stable and ultra-sensitive detection of nanotargets

Preparatory Courses:

Introduction to Optical Sensing Techniques, Laser Spectroscopy

Vibrational and mass spectroscopies for investigating human cell interactions with physico-chemical agents.

Titolo Tesi:
Vibrational and mass spectroscopies for investigating human cell interactions with physico-chemical agents.

Thesis Supervisors:
Int.: [ Maria Lepore ] [ Marianna Bianca Emanuela Portaccio ] [ Nadia Diano ]
Ext.: [ ]

Brief Description:

The joint use of vibrational and mass spectroscopies allows the investigation of the interaction processes between human cells and different external agents, as ionizing and non-ionizing radiation, environmental pollutants, and nutraceutical compounds. The results of these studies can be usefully applied in the developments of new medical diagnostic and environmental monitoring techniques.

Preparatory Courses:

Applied Biophotonics, Photonics and Nanotechnologies

Correlations of active tracers in lattice gas models

Titolo Tesi:
Correlations of active tracers in lattice gas models

Thesis Supervisors:
Int.: [ Alessandro Sarracino ] [ Eugenio Lippiello ]
Ext.: [ ]

Brief Description:

Active particles are characterized by internal mechanisms of energy consumption that allow for persistent motion. Typical examples can be found in the biological world (from bacteria at small scales to birds and fishes) or in man-made small objects (micro and nano-devices). They represent non-equilibrium systems due to the continuous exchange of energy and heat with the surrounding environment and many interesting phenomena have been observed when a large number of interacting active particles is considered. Among the several models proposed to describe such systems, lattice gases, where particles can jump on the sites of a discrete lattice with specific interaction rules, have been recently studied both numerically and analytically. The thesis project aims at exploring the interesting open question related to the study of the behavior of correlations between few active tracers immersed in a bath of passive particles.

Preparatory Courses:

Statistical Mechanics, Modeling of Complex Systems

Fluctuation-Dissipation theorem applied to neural models

Titolo Tesi:
Fluctuation-Dissipation theorem applied to neural models

Thesis Supervisors:
Int.: [ Lucilla De Arcangelis ] [ Alessandro Sarracino ]
Ext.: [ ]

Brief Description:

The brain represents one of the most fascinating systems where several mechanisms at different scales are deeply intertwined, resulting in a complex behavior. One of the main open issues in the understanding of brain functioning is the relation between spontaneous and evoked activity, namely the response of the system to external stimuli. This question can be addressed theoretically within the general framework of statistical physics, by means of the fluctuation-dissipation relations, connecting the spontaneous fluctuations of a system with the response function to external perturbations. The thesis project aims at exploring the possibility to apply these theoretical tools to specific stochastic neural models and to experimental data for brain activity.

Preparatory Courses:

Statistical Mechanics, Modeling of Complex Systems

Scaling of avalanche shape and activity power spectrum in neuronal networks

Titolo Tesi:
Scaling of avalanche shape and activity power spectrum in neuronal networks

Thesis Supervisors:
Int.: [ Lucilla De Arcangelis ] [ Alessandro Sarracino ]
Ext.: [ ]

Brief Description:

Many systems in nature exhibit avalanche dynamics with scale-free features. A general scaling theory has been proposed for critical avalanche profiles in crackling noise, predicting the collapse onto a universal avalanche shape, as well as the scaling behavior of the activity power spectrum as Brown noise. Recently, much attention has been given to the profile of neuronal avalanches, measured in neuronal systems in vitro and in vivo. Although a universal profile was evidenced, confirming the validity of the general scaling theory, the parallel study of the power spectrum scaling under the same conditions was not performed. The puzzling observation is that in most healthy neuronal systems the power spectrum exhibits a behavior close to 1/ f, rather than Brown, noise. Numerical results on the scaling behavior of the avalanche shape and the power spectrum for a model of integrate and fire neurons confirm that the average avalanche size and the avalanche profile fulfill the general avalanche scaling theory. However, the power spectrum consistently exhibits Brown noise behavior, for both fully excitatory networks and systems with 30% inhibitory neurons. Conversely, a behavior closer to 1/ f noise is observed in systems slightly off criticality. Results suggest that the power spectrum is a good indicator to determine how close neuronal activity is to criticality. This project aims to verify such prediction in different brain datasets and in healthy and pathological conditions.

Preparatory Courses:

Statistical Mechanics, Modeling of Complex Systems

Topological optimization of sensor networks for environmental risk assessment

Titolo Tesi:
Topological optimization of sensor networks for environmental risk assessment

Thesis Supervisors:
Int.: [ Eugenio Lippiello ] [ Alessandro Sarracino ] [ Lucilla De Arcangelis ]
Ext.: [ ]

Brief Description:

The thesis project will focus on the study of wireless sensor networks (WSNs) used to monitor various environmental aspects, including climate, air pollution, water quality, biodiversity, and seismic risk. Specifically, activity will concentrate on identifying the most efficient communication protocol between pairs of sensors to improve the efficiency and robustness of the network. This research line will employ mathematical tools from percolation theory integrated with specific aspects of WSNs, requiring interdisciplinary training including non-equilibrium statistical mechanics and communication engineering.

Preparatory Courses:

Statistical Mechanics, Modeling of Complex Systems, Network Science

Testing the potential impact of foreshock occurrence in the improvement of seismic risk management

Titolo Tesi:
Testing the potential impact of foreshock occurrence in the improvement of seismic risk management

Thesis Supervisors:
Int.: [ Eugenio Lippiello ] [ Cataldo Godano ] [ Lucilla De Arcangelis ]
Ext.: [ ]

Brief Description:

The thesis project aims to address the question of whether foreshocks can be reliable precursors for large earthquakes. Historical records highlight the significant impact of earthquakes on human history and the ongoing search for reliable warning signs preceding destructive earthquakes. While foreshocks have been considered a promising candidate for earthquake forecasting, their potential usefulness remains uncertain. The project will utilize statistical and deep learning methodologies to identify distinct spatio-temporal patterns associated with foreshock occurrence in seismic catalogs. The objective is to establish empirical laws for foreshocks and incorporate them into epidemic models to minimize discrepancies between synthetic and instrumental catalogs. The study aims to enhance seismic risk reduction capabilities, improve preparedness, and resilience by measuring the actual knowledge gain from foreshock identification. The project also explores the extraction of foreshock patterns from waveform properties recorded at a single seismic station.

Preparatory Courses:

Statistical Mechanics, Modeling of Complex Systems

Non-equilibrium dynamics of interfaces with long-range interactions: from theory towards applications

Titolo Tesi:
Non-equilibrium dynamics of interfaces with long-range interactions: from theory towards applications

Thesis Supervisors:
Int.: [ Eugenio Lippiello ] [ Alessandro Sarracino ] [ Lucilla De Arcangelis ]
Ext.: [ ]

Brief Description:

The role of interfaces in various physical systems is crucial for understanding their properties and applications. These systems include ferromagnetic and ferroelectric materials, superconductors, complex fluids, colloidal systems, liquid crystals, polymers, and composite materials. Interfaces also play a significant role in phenomena like cancer invasion. When disorder is present, interfaces respond to changes through discrete, rapid events that occur across a wide range of sizes. Examples of such intermittent dynamics with scale-free statistics can be seen in earthquake occurrences and neuronal avalanches. This master thesis project aims to conduct a comprehensive statistical-mechanical investigation of the non-equilibrium kinetics of elastic interfaces in random media with long-range interactions. The project will explore this problem as well as its variations, such as the non-equilibrium kinetics of quenched long-range binary systems with or without quenched disorder, seismic models involving faults described by interfaces with long-range elasticity, and a modeling of brain activity considering non-uniform, long-range correlated connectivity among neurons.

Preparatory Courses:

Statistical Mechanics, Modeling of Complex Systems, Network Science

The variational quantum eigensolver algorithm

Titolo Tesi:
The variational quantum eigensolver algorithm

Thesis Supervisors:
Int.: [ Giovanni De Gregorio ]
Ext.: [ ]

Brief Description:

The variational quantum eigensolver algorithm (or VQE) has received significant attention from the research community in recent years. It uses the variational principle to compute the ground state energy of a Hamiltonian, a problem that is central for example in quantum chemistry, in condensed matter physics, and, in general when dealing with a quantum many-body system. The objective of the thesis is to implement a simple Hamiltonian, like the pairing Hamiltonian, and study features and drawbacks of the algorithm via simulation and direct implementation on the IBM QPUs.

Preparatory Courses:

Quantum Computing

Encoding a two-body Hamiltonian on a quantum computer

Titolo Tesi:
Encoding a two-body Hamiltonian on a quantum computer

Thesis Supervisors:
Int.: [ Giovanni De Gregorio ]
Ext.: [ ]

Brief Description:

The main problem to face in the solution of an eigenvalue problem on a Quantum computer is the encoding of the Hamiltonian, i.e. the mapping used to transform the fermionic, second quantized Hamiltonian into a weighted sum of Pauli operators. The goal of the thesis is to try different encoding schemes to implement a generic two-body Hamiltonian for solving the Hartree-Fock problem on a quantum computer.

Preparatory Courses:

Quantum Computing

Machine Learning the nuclear shell model

Titolo Tesi:
Machine Learning the nuclear shell model

Thesis Supervisors:
Int.: [ LUIGI CORAGGIO ] [ Nunzio Itaco ] [ Giovanni De Gregorio ]
Ext.: [ ]

Brief Description:

The nuclear shell model is one of the most adopted many-body methods to solve the nuclear eigenvalue problem. Despite the development of more and more sophisticated codes able to exploit the capability of the modern HPC clusters, often one must deal with model space dimensions too big for the diagonalization. The goal of the thesis project is to use Machine Learning techniques to reduce a priori the dimension of the model space.

Preparatory Courses:

Theoretical Physics, Microscopic Nuclear Structure

Many-Body Nuclear Systems with Low-Energy Effective Field Theory Potential Models

Titolo Tesi:
Many-Body Nuclear Systems with Low-Energy Effective Field Theory Potential Models

Thesis Supervisors:
Int.: [ LUIGI CORAGGIO ] [ Giovanni De Gregorio ] [ Nunzio Itaco ]
Ext.: [ ]

Brief Description:

In the last decades, effective field theory (EFT) has become the

standard approach to the nuclear interaction problem, based on

separation of scales and providing a direct link to the underlying theory

of the strong interaction (QCD).

Accurate nuclear potentials and currents have been derived in chiral

EFT (ChEFT) at large orders of the low-energy expansion, and a drastic

simplification in their operatorial structure results when pions can

be integrated out, in the very low-energy regime (low-energy EFT - LEEFT).

Recently, an accurate two-nucleon (2N) potential has been determined

within LEEFT, including three orders of the expansion (N3LO), in

conjunction with a leading-order (LO) three-nucleon (3N) force.

The aim of this master thesis is the investigation of many-body nuclear

systems, ranging from light- and medium-mass nuclei up to infinite

nuclear matter, using the LEEFT potential models.

In this context, the treatment of the 3N force of the LEEFT Hamiltonian

will be of particular importance.

Preparatory Courses:

Theoretical Physics - Microscopic Nuclear Structure

Investigation of the 7Be electron capture in different environments

Titolo Tesi:
Investigation of the 7Be electron capture in different environments

Thesis Supervisors:
Int.: [ Lucio Gialanella ] [ Raffaele Buompane ]
Ext.: [ ]

Brief Description:

7Be has been gaining an increasing interest in basic and applied research in the last decades. Its decay mode, pure electron capture, and its low atomic number make it an ideal system to probe the nucleus through the modification of the environmental conditions. The dependence of the 7Be half-life on the electronic density has been studied by measuring the change of the 7Be half-life in different chemical compounds, crystal lattices and nanostructures. In all these cases a quantitative description of the results is complicated by the complex environment in which the decay takes place. A much simpler situation could be obtained studying the decay of 7Be ions. To achieve that, experiments were proposed at storage rings, so far without success. The thesis will be completed in the framework of the project ASBeST (A 7Be STudy for nuclear and solid state physics) project, that aims to study the 7Be electron capture decay for the first time under controlled conditions by exploiting two novel approaches. On the one hand, measurements of the half-life of 7Be ions in different charge states will be performed using an intense 7Be ion beam and accelerator mass spectrometry techniques. On the other, the Stark effect in solids will be produced in Silicon Carbide (SiC) based electronic devices. The results will be used to determine with high precision the nuclear matrix elements of the weak interaction, that will be compared with the outcome of a fully microscopic calculation. Based on that, it will be possible to investigate the details of the 7Be decay, in particular the K/L electron capture ratio. The expected impact of the results obtained is beyond nuclear physics alone. In particular, the possibility of using 7Be as a probe of the local electric field in high field electronic devices will be investigated. Finally, the competition between proton and electron capture on 7Be in the Sun and its impact on the observed solar neutrino spectrum will be revised

Preparatory Courses:

Nuclear and subnuclear physics, Theoretical physics

Measurement of the cross section of 12C(a,g)16O at astrophysical energies of interest

Titolo Tesi:
Measurement of the cross section of 12C(a,g)16O at astrophysical energies of interest

Thesis Supervisors:
Int.: [ Raffaele Buompane ] [ Lucio Gialanella ]
Ext.: [ ]

Brief Description:

The ERNA (European Recoil for Nuclear Astrophysics) experiment studies nuclear processes of astrophysical interest with different methodologies, in particular with the ERNA recoil separator, installed at the CIRCE Laboratory of the University of Campania.

The study of the 12C(a,g)16O reaction with the separator is currently underway. This reaction is very important because it affects the ratio of carbon to oxygen left by helium burning. The oxygen-carbon ratio has a deep impact on the advanced phases of stellar evolution and the ultimate fate of stars. The candidate will be involved in the planned experimental activity, making measurements with the ERNA recoil separator and participating in the analysis of reaction data.

Preparatory Courses:

Nuclear and subnuclear physics, Nuclear astrophysics

Mid-infrared ethylene spectroscopy for the FAMU experiment

Titolo Tesi:
Mid-infrared ethylene spectroscopy for the FAMU experiment

Thesis Supervisors:
Int.: [ Livio Gianfrani ] [ Eugenio Fasci ] [ Luigi Moretti ]
Ext.: [ ]

Brief Description:

The FAMU (Fisica degli Atomi MUonici) collaboration, supported by the National Institute for Nuclear Physics, is doing an experiment for the first hyperfine splitting measurement of the muonic hydrogen (μp) ground state at the muon beam facility of the Rutherford-Appleton Laboratory (RAL), UK. The experiment aims to perform a determination of the proton size with higher precision (<1%) than previously possible. Such an ambitious goal requires an accurate frequency calibration at the wavelength region nearby 6789 nm, with a direct traceability to the SI frequency standard. This is possible by exploiting the absorption spectrum of ethylene, which is an asymmetric top molecule with 12 normal modes of vibration. The v₁₂ fundamental vibrational band exhibits strong components in coincidence with the expected wavelength of the μp spin-flip transition. Within the MENPHYS project (funded in the framework of the PRIN2022 Program), the knowledge of these lines will be significantly improved, thus reaching the sub-MHz level of uncertainty for the central frequencies. To this aim, a mid-infrared comb-calibrated laser spectrometer is being developed. The apparatus is based upon the joint use of a continuous wave, room-temperature, distributed feedback (DFB) quantum cascade laser (QCL) and a self-referenced near-infrared Er-doped fiber-laser COMB. An up-conversion process in a nonlinear crystal should be performed by means of Sum Frequency Generation. Such scheme allows the QCL frequency to be directly referred to the repetition frequency of the comb without any contribution from the carrier-envelope-offset frequency. Tuning of the repetition-rate will allow to perform comb-calibrated frequency scans of the QCL throughout the absorption lines of interest. High-quality absorption spectra will be recorded at different gas pressures in an isothermal cell. From nonlinear least-squares fits of the line profiles (based upon the most refined semiclassical models), the zero-pressure absolute center frequencies will be retrieved with a global uncertainty of about 100 kHz.

Preparatory Courses:

Quantum Electronics for Atomic Physics; Laser Spectroscopy

Investigation of electromagnetic induced transparency in mercury vapors: a new platform for quantum technologies

Titolo Tesi:
Investigation of electromagnetic induced transparency in mercury vapors: a new platform for quantum technologies

Thesis Supervisors:
Int.: [ Livio Gianfrani ] [ Stefania Gravina ]
Ext.: [ ]

Brief Description:

Electromagnetically-induced transparency (EIT) is a nonlinear optical phenomenon observed in atomic systems with a three-level energy structure. Introduced by Stephen Ernest Harris and co-workers at Stanford University in 1990, EIT exploits quantum interference to induce transparency within a resonant and otherwise opaque medium. In other words, the transmission of a probe beam through an optically dense medium is manipulated by means of a control beam. Therefore, EIT offers the possibility to control light with light. For this reason, it is attracting a growing interest for quantum information and quantum sensing technologies, including the practical realization of light storage and quantum memory devices.

There are three possible configurations for a three-level structure, known as lambda (Λ), vee (V) and ladder schemes. We intend to perform high-resolution spectroscopy of mercury vapors employing an original ladder-type EIT configuration. In this scheme, EIT manifests as optical transparency at wavelengths nearby the atomic transition from the ground state |g> to the excited state |e>, which normally exhibits significant attenuation, and an associated reduction in group velocity of the incident signal field. This transparency and slowed group velocity is due to the presence of a second, strong, optical control field which couples the excited state with an upper one (|s>), where the |s>→|e> transition is electric-dipole allowed while the |s>→|g> transition is forbidden.

Specifically, our EIT scheme involves a weak probe field nearby the intercombination transition of mercury from the ground state 6¹S₀ to the excited state 6³P₁ at 253.7 nm. Coherent deep-UV radiation is generated by means of a frequency-quadrupled scheme of an extended cavity diode laser (ECDL) at 1014.8 nm in a pair of nonlinear crystals. The near-infrared radiation is locked to an optical frequency comb, which in turn is stabilized against an ultra-stable GPS-disciplined Rb clock. In this way, we are able to perform comb-calibrated UV frequency scans throughout the intercombination line by tuning the comb repetition-rate.

The experiment aims to observe EIT for the ²⁰⁰Hg bosonic and ¹⁹⁹Hg fermionic isotopes to investigate the influence of hyperfine structure effects. We intend to acquire and analyse experimental transmission profiles of the signal beam as a function of control frequency shift for different levels of the resonant control-field power within the warm atomic system.

Preparatory Courses:

Quantum Electronics for Atomic Physics; Laser Spectroscopy

Cold hydrogen molecules for spectroscopic tests of fundamental interactions.

Titolo Tesi:
Cold hydrogen molecules for spectroscopic tests of fundamental interactions.

Thesis Supervisors:
Int.: [ Livio Gianfrani ]
Ext.: [ Questo indirizzo email è protetto dagli spambots. È necessario abilitare JavaScript per vederlo. ]

Brief Description:

The thesis work will focus on the realization of quantum sensors of fundamental Physics, based on the production of molecular samples at cryogenic temperatures by the buffer-gas-cooling (BGC) technique, and their combination with cavity-enhanced precision spectroscopy in the Lamb-dip regime. In particular, we aim to set new bounds on putative fifth forces beyond the Standard Model, by accomplishing sub-kHz-accuracy line-center frequency determinations for selected hydrogen deuteride (HD) ro-vibrational transitions in the (2,0)/(1,0) overtone/fundamental band at 1.4/2.7 micron wavelength. To address this challenge, a modern BGC source will be first realized to create 20-Kelvin HD samples, thus providing enhanced absorption cross sections and matter-radiation interaction times. Then, a metrological-grade infrared laser source will be coupled to a high-finesse cavity with superior mechanical stability surrounding the cold HD sample, to implement either the noise-immune cavity-enhanced optical-heterodyne molecular-spectroscopy (NICE-OHMS) or the saturated-absorption cavity ring-down (SCAR) technique. Ultimately, comparison of the measured transition frequencies with state-of-the-art ab initio calculations will constrain the coupling strength of extra long-range (Angstrom length scales) hadron-hadron interactions below 10-10α (being α the fine-structure constant), one order of magnitude better than the present limit.

Preparatory Courses:

Quantum Electronics for Atomic Physics; Laser Spectroscopy