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Tunable spin and valley excitations of correlated insulators in $\Gamma$-valley moir\'e bands
- Publication Year :
- 2022
-
Abstract
- Moir\'e superlattices formed from transition metal dichalcogenides (TMDs) have been shown to support a variety of quantum electronic phases that are highly tunable using applied electromagnetic fields. While the valley character of the low-energy states dramatically affects optoelectronic properties in the constituent TMDs, this degree of freedom has yet to be fully explored in moir\'e systems. Here, we establish twisted double bilayer WSe$_2$ as an experimental platform to study electronic correlations within $\Gamma$-valley moir\'e bands. Through a combination of local and global electronic compressibility measurements, we identify charge-ordered phases at multiple integer and fractional moir\'e band fillings $\nu$. By measuring the magnetic field dependence of their energy gaps and the chemical potential upon doping, we reveal spin-polarized ground states with novel spin polaron quasiparticle excitations. In addition, an applied displacement field allows us to realize a new mechanism of metal-insulator transition at $\nu = -1$ driven by tuning between $\Gamma$- and $K$-valley moir\'e bands. Together, our results demonstrate control over both the spin and valley character of the correlated ground and excited states in this system.
Details
- Database :
- arXiv
- Publication Type :
- Report
- Accession number :
- edsarx.2206.10631
- Document Type :
- Working Paper
- Full Text :
- https://doi.org/10.1038/s41563-023-01534-z