Heavy fermions and superconductivity in heterobilayer TMDs

In this presentation, we study the multiband physics of transition metal dichalcogenides (TMDs) bilayers, where the density of carriers, interaction strength, and energy offset between orbitals are experimentally adjustable across wide ranges. The tunability of these parameters enables unprecedented control over the ground state, offering exciting possibilities for the synthetic realization and systematic exploration of various intriguing phenomena, including site/orbitally selective Mott transitions, heavy-Fermi liquids, Quantum anomalous Hall insulators, and the potential emergence of superconductivity. 

Our focus centers on a detailed analysis of the "heavy fermion" regime, where we unveil an interesting interplay between strong spin-orbit coupling and a non-local structure, leading to a chiral Kondo coupling that introduces a new twist to the realm of heavy fermion physics [1]. Moreover, we investigate the stability of magnetic order against Kondo screening, resulting in the discovery of a nodal Kondo insulator state. Lastly, we show that within the small Fermi surface regime, a charge 2e quaternion excitation plays a crucial role in mediating effective attractive interactions between doped charges. This interaction favors a p+ip superconducting order parameter, ultimately giving rise to the realization of the Z2 topological superconductor [2,3]. Our theoretical framework draws inspiration from experimental studies in AB-stacked TMD bilayer MoTe2/WSe2 [4,5] and sheds light on the intricate multiband physics of TMD bilayers.

Refs.

[1] D. Guerci, J. Wang et al., Science Advances 9, 11, (2023) 

[2] V. Crepel, D. Guerci et al, arXiv: (2023) [accepted to PRL (Editor's suggestion)] 

[3] D. Guerci, V. Crepel et al. in preparation 

[4] Kin Fai Mak et al., Nature 600, 641 (2021) 

[5] Wenjin Zhao et al., Nature (2023)

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