Unconventional pathways to unconventional superconductivity

John Sous
Columbia University
Monday, February 14, 2022
11:00 am
ISEB 1200 [Interdisciplinary Science and Engineering Building]
Superconductivity represents a striking state of matter characterized by dissipationless flow of current.  In this talk, I will present new, unconventional pathways to realizing unconventional superconductivity from relatively simple ingredients.  I will first review conventional superconductivity in which phonons mediate electronic pairing and superconducting behavior, and discuss limitations on Tc at strong electron-phonon coupling.  I will then present three new unconventional pathways to circumvent these limitations: 1. Superconductivity from superfluidity of light bipolarons which arise from strong electron-bond-phonon coupling at small electronic densities where conventional limitations on Tc do not hold, 2. Superconductivity in novel organic materials such as the recently synthesized alkali-doped terphenyl crystals from strong local electronic correlations in quasi-one-dimensional ladder geometry, and 3. Dynamically-induced superconductivity (and disorder) in optically driven metals whose vibrational modes are 'pumped' at initial time and whose response is 'probed' at later times by means of tailored light pulses.
Alexander Chernyshev
Judit Romhanyi