Published May 2, 2025 | Published
Journal Article Open

Quantum Geometric Kohn-Luttinger Superconductivity

  • 1. ROR icon California Institute of Technology

Abstract

Coulomb repulsion can, counterintuitively, mediate Cooper pairing via the Kohn-Luttinger mechanism. However, it is commonly believed that observability of the effect requires special circumstances, e.g., vicinity of the Fermi level to Van Hove singularities, significant lattice-induced band distortions, or nontrivial Fermi surface topologies. Here, we establish that quantum geometric properties of the constituent electrons can dramatically promote pairing from repulsion via dependence of screening on the quantum metric. We demonstrate quantum-geometry-enhanced superconductivity in two microscopic models with tunable quantum geometry, highlighting the crucial roles of quantum metric anisotropy and inhomogeneity. Our analysis provides an experimentally accessible figure of merit for the importance of quantum geometry to inducing unconventional superconductivity, indicating its relevance to graphene multilayers.

Copyright and License

© 2025 American Physical Society

Acknowledgement

We thank Patrick A. Lee and Trithep Devakul for helpful discussions. G. S. acknowledges support from the Walter Burke Institute for Theoretical Physics at Caltech, and from the Yad Hanadiv Foundation through the Rothschild fellowship. This work was also partially supported by the U.S. Department of Energy, Office of Science, National Quantum Information Science Research Centers, Quantum Science Center (J. A., for discussions and manuscript preparation).

Supplemental Material

The SM file contains details on the band projected Hamiltonian, RPA calculations, BCS gap equation and its extensions, calculations for the TM and TBI models, geometry-induced chiral superconductivity, and geometric effects on conventional superconductivity.

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Additional details

Created:
April 30, 2025
Modified:
April 30, 2025