Dottore di ricerca

ciclo: XXXV

relatore: Prof. F. Mauri ; Dott. P. Barone
co-supervisore: Prof. L. Benfatto

Titolo della tesi: Ab initio method for vibrational spectroscopy in conductive systems

Cooperative phenomena in solid-state physics have gained significant attention due to their scientific and technological importance. This relevance was officially acknowledged in the Ginzburg Nobel Lecture in 2004, which emphasized the pursuit of high-temperature superconductivity as a key challenge for the 21st century. Recent technological advancements have enabled a more profound exploration of these phenomena, gathering instances where electronic cooperation is mediated by phonon interactions. However, this research faces experimental challenges that hinders sample characterization. Vibrational spectroscopy plays a key role in sample characterization, especially infrared reflectivity measurement in case of high-pressure environment where the diamond-anvil-cell apparatus is required. However until recent years, the theoretical description of this experimental technique was confined to insulating systems. Up to now, there is no formulation describing the vibrational contribution to the susceptibility in the damped regime, where scattering effect are non-negligible. This unconventional scenario occurs in systems showing cooperative phenomena mediated by the phonon interaction, since the same interaction at the origin of the cooperative phenomenon also provides a potent scattering mechanism. This thesis proposes a theoretical approach and computational methods to calculate the vibrational response in metals, extending the present formulation to the time domain and damped regime. We apply this method to MgB$_2$ and two super-Hydrides: H$_3$S and LaH$_{10}$ where the strong electron-phonon coupling is considered the origin of their exceptional high critical temperature as conventional BCS superconductors.

Produzione scientifica

11573/1701121 - 2024 - Infrared resonance Raman of Bilayer graphene. Signatures of massive Fermions and band structure on the 2D peak
Graziotto, Lorenzo; Macheda, Francesco; Venanzi, Tommaso; Marchese, Guglielmo; Sotgiu, Simone; Ouaj, Taoufiq; Stellino, Elena; Fasolato, Claudia; Postorino, Paolo; Metzelaars, Marvin; Kögerler, Paul; Beschoten, Bernd; Calandra, Matteo; Ortolani, Michele; Stampfer, Christoph; Mauri, Francesco; Baldassarre, Leonetta - 01a Articolo in rivista
rivista: NANO LETTERS (Washington, DC : American Chemical Society, c2001-) pp. 1867-1873 - issn: 1530-6984 - wos: (0) - scopus: 2-s2.0-85184820749 (1)

11573/1693578 - 2024 - EPIq. An open-source software for the calculation of electron-phonon interaction related properties
Marini, Giovanni; Marchese, Guglielmo; Profeta, Gianni; Sjakste, Jelena; Macheda, Francesco; Vast, Nathalie; Mauri, Francesco; Calandra, Matteo - 01a Articolo in rivista
rivista: COMPUTER PHYSICS COMMUNICATIONS (Amsterdam: Elsevier BV) pp. 1-39 - issn: 0010-4655 - wos: WOS:001102536700001 (2) - scopus: 2-s2.0-85174812925 (2)

11573/1693576 - 2023 - Born effective charges and vibrational spectra in superconducting and bad conducting metals
Marchese, G.; Macheda, F.; Binci, L.; Calandra, M.; Barone, P.; Mauri, F. - 01a Articolo in rivista
rivista: NATURE PHYSICS (npg: nature publishing group) pp. 88-94 - issn: 1745-2473 - wos: (0) - scopus: 2-s2.0-85174939796 (0)

11573/1412083 - 2020 - Experimental violation of n-locality in a star quantum network
Poderini, D.; Agresti, I.; Marchese, G.; Polino, E.; Giordani, T.; Suprano, A.; Valeri, M.; Milani, G.; Spagnolo, N.; Carvacho, G.; Chaves, R.; Sciarrino, F. - 01a Articolo in rivista
rivista: NATURE COMMUNICATIONS (London: Nature Publishing Group-Springer Nature) pp. - - issn: 2041-1723 - wos: WOS:000536698500010 (36) - scopus: 2-s2.0-85084911170 (43)

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