Who: Maria Navarro Gastiasoro, ISC-CNR and Sapienza University of Rome, Italy
Place: Hybrid Seminar, Donostia International Physics Center
Date: Tuesday, 24 May 2022, 12:00
Superconductivity in doped quantum paraelectric materials develops in proximity to a ferroelectric phase. An intimate relation between the superconducting and ferroelectric phases has been experimentally established in SrTiO3, a model incipient ferroelectric. Quantum critical fluctuations of the ferroelectric order open the possibility of a novel pairing mechanism. In this talk I will present a minimal microscopic model for the linear coupling between electrons and the ferroelectric mode (a soft transverse optical phonon) in a system with spin-orbit coupling. Remarkably, the Cooper pairing interaction resulting from this Rashba-like coupling is attractive in even-parity (s-wave) as well as odd-parity (p- wave) channels. I will show how to estimate the bare Rashba coupling and BCS pairing coupling constant with the aid of first-principles computations in SrTiO3. This approach can be easily extended to other incipient ferroelectrics and interfaces.
Host: Fernando de Juan