Jonah HERZOG-ARBEITMAN. From weak to strong correlations in twisted materials: Graphene and MoTe2

Contact: andrej.mesaros@universite-paris-saclay.fr

Jonah HERZOG-ARBEITMAN, Department of Physics, Princeton University

Le résumé :

   The moiré platform has expanded since the discovery of twisted bilayer graphene to new materials, probes, and phases of matter.

   We showcase recent discoveries in interacting physics across three moiré platforms. We first introduce the Quantum Twisting Microscope (QTM), a remarkable new platform leveraging moiré tunneling to resolve 2D band structures and thermodynamic quantities. Using QTM data from D. Efetov’s group, we show new measurements of graphene’s Fermi velocity renormalization that yield detailed information on both short-range and long-range interactions even at room temperature. We then explain how this same interaction Hamiltonian is transformed in the flat bands of rhombohedral graphene superlattices to yield fractional Chern insulators, addressing a series of experiments and resolving the origin of the strong moiré potential in the system.

   Fractional Chern insulators (FCIs) first appeared in moiré systems after their discovery in twisted MoTe2 thanks to the confluence of flat bands, magnetism, and topology. While FCIs resemble the fractional quantum Hall effect in many ways, we point out a crucial novel feature: the possibility of dispersive anyons. We perform exact diagonalization calculations in a realistic model of MoTe2 and present the microscopic anyon band structure at 2/3 filling.