Dark Matter Detection with Strongly Correlated Topological Matter: Flatband Effect

Dirac materials have been proposed as a new class of electron targets for light dark-matter (DM) scattering or absorption, with their sensitivity superior to superconductors and superfluid helium. This superiority is obtained by the gain from the significantly reduced in-medium effect over the suppression of DM scattering phase space at the point-like Fermi surface in a Dirac material. Here we propose materials with strong electron correlations for DM detection. By considering a strongly correlated Weyl semimetal model system, we demonstrate that the correlation effect can amplify significantly the coupling or detection sensitivity to light DM particles. This amplification comes from the strong correlation-induced band renormalization, which enhances the scattering phase space on the one hand and retain the reduced in-medium effect on the other hand.