The Joint Condensed Matter Seminar (JCMS) series is organised by KTH Royal Insitute of Technology, Nordita, and Stockholm University.
On Monday, January 23rd, 2023 from 11 am to 12 am we will host a seminar by Tim Wehling from University of Hamburg.
Coherence and pairing fluctuations in strongly correlated superconductors
The fundamental properties of superfluids and superconductors are determined by the spatial coherence of the macroscopic condensate. Central to this characterization is the knowledge of the coherence length 𝜉, as it specifies the relevant length scales for fluctuations pertinent to, e.g., the formation of vortex latices or magneto-thermal transport. While the description of 𝜉 is well established in weak-coupling BCS theory and Eliashberg-theory, it is a generally unknown quantity in strongly correlated superconductors, where spatiotemporal fluctuations influence the critical temperature [1] and might underlie light-induced enhancement of superconductivity [2].
We discuss how to access coherence lengths for superconductors with strong electron correlations from microscopic theories and first principles. We illustrate with the example of Alkali-doped fullerides (A3C60) how proximity of superconducting and Mott-localized states impact superconducting coherence, pairing fluctuations, and critical temperature. Our analysis shows Eliashberg-type behavior of strongly correlated superconductors.
[1] Emery & Kivelson, Nature 374 (1995).
[2] Fausti et al., Science 331 (2011); Mitrano et al., Nature 530 (2016).