Tunable spin and valley excitations of correlated insulators in Γ-valley moiré bands.
Moiré superlattices formed from transition metal dichalcogenides support a variety of quantum electronic phases that are highly tunable using applied electromagnetic fields. While the valley degree of freedom affects optoelectronic properties in the constituent transition metal dichalcogenides, it has yet to be fully explored in moiré systems. Here we establish twisted double-bilayer WSe2 as an experimental platform to study electronic correlations within Γ-valley moiré bands. Through local and global electronic compressibility measurements, we identify charge-ordered phases at multiple integer and fractional moiré fillings. By measuring the magnetic field dependence of their energy gaps and the chemical potential upon doping, we reveal spin-polarized ground states with spin-polaron quasiparticle excitations. In addition, an applied displacement field induces a metal-insulator transition driven by tuning between Γ- and K-valley moiré bands. Our results demonstrate control over the spin and valley character of the correlated ground and excited states in this system.
View details for DOI 10.1038/s41563-023-01534-z
View details for PubMedID 37069292
Interaction-driven spontaneous ferromagnetic insulating states with odd Chern numbers
NPJ QUANTUM MATERIALS
2023; 8 (1)
View details for DOI 10.1038/s41535-023-00544-z
View details for Web of Science ID 000948370100001
Correlated Hofstadter spectrum and flavour phase diagram in magic-angle twisted bilayer graphene
View details for DOI 10.1038/s41567-022-01589-w
View details for Web of Science ID 000787131300001