20–23 Jun 2022
Max Planck Institut für Festkörperforschung
Europe/Berlin timezone

Superconductivity without quasiparticles: Quantum critical Eliashberg theory and its holographic dual

20 Jun 2022, 11:15
30m
2D5 (Max Planck Institut für Festkörperforschung)

2D5

Max Planck Institut für Festkörperforschung

Keynote Talk / Invited Talk Quantum Criticality and Superconductivity

Speaker

Jörg Schmalian (Karlsruhe Institute of Technology)

Description

Superconductivity is abundant near quantum-critical points, where fluctuations suppress the formation of Fermi liquid quasiparticles and the Bardeen-Cooper-Schrieffer theory no longer applies. Two very distinct approaches have been developed to address this issue: quantum-critical Eliashberg theory and holographic superconductivity. The former includes a strongly retarded pairing interaction of ill-defined fermions, the latter is rooted in the duality of quantum field theory and gravity theory. We demonstrate that both are different perspectives of the same theory. We derive holographic superconductivity in form of a gravity theory with emergent space-time from a quantum many-body Hamiltonian - the Yukawa SYK model and finite-dimensional generalizations thereof - where the Eliashberg formalism is exact. Exploiting the power of holography, we then determine the dynamic pairing susceptibility of the model. Our holographic map comes with the potential to use quantum gravity corrections to go beyond the Eliashberg regime.

Primary author

Jörg Schmalian (Karlsruhe Institute of Technology)

Presentation materials

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