Season 9 Episode 2 PhD Seminar

Wednesday 7 Feb 2024, 18:15 → 19:15 Europe/Rome

Aula Conversi (VEF) and Zoom

41th meeting of physics PhD seminar series

https://uniroma1.zoom.us/j/87038625161

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https://groups.google.com/u/1/a/uniroma1.it/g/phd-seminars

You can submit abstracts using the following link:

https://forms.gle/FAKjaQMUoy3ZwHEY9

18:15 → 18:35 LISA mission: from the experiment to the potential discoveries

Gravitational waves detected by the ground-based interferometers LIGO, Virgo and Kagra have opened the way to new scenarios and provided new tools to get a deeper understanding of our universe. One of the most promising ways to detect those signals in the future will be with a detector settled-up in the space known as Laser Interferometer Space Antenna (LISA). In this talk, we will introduce the experimental set-up, as well as its goals and the new potential sources that could detect.

Speaker: Francesco Crescimbeni

Ph.D. Seminar Talk.ppt

18:35 → 18:45 Dicussion

18:45 → 19:05 Two-phonon pairing does not explain superconductivity in strontium titanate

The unconventional and antiadiabatic nature of strontium titanate (STO) makes the BCS paradigm not directly applicable. Although experimental evidence indicates a connection between the superconductivity and a ferroelectric quantum critical point, the pairing mechanism is still not known. We study a mechanism mediated by two polar transverse modes associated with the incipient ferroelectric instability. We derive the effective two-phonon mediated electron-electron interaction in the Migdal-Eliashberg formalism, including time dependence and retardation effects. We conclude that the estimated coupling parameter of the two-phonon interaction for STO is too small to reproduce a finite critical temperature.

Speaker: Antonio Santacesaria

PhD Sem.pptx

19:05 → 19:15 Discussion