Confined Trions and Mott-Wigner States in a Purely Electrostatic Moiré Potential

Abstract

Moiré heterostructures consisting of transition metal dichalcogenide (TMD) hetero- and homobilayers have emerged as a promising material platform to study correlated electronic states. Optical signatures of strong correlations in the form of Mott-Wigner states and fractional Chern insulators have already been observed in TMD monolayers and their twisted bilayers. In this work, we use a moiré substrate containing a twisted hexagonal boron nitride (h-BN) interface to externally generate a superlattice potential for the TMD layer: the periodic structure of ferroelectric domains in h-BN effects a purely electrostatic potential for charge carriers. We find direct evidence for the induced moiré potential in the emergence of new excitonic resonances at integer fillings, and our observation of an enhancement of the trion binding energy by $\simeq$ 3 meV. A theoretical model for exciton-electron interactions allows us to directly determine the moiré potential modulation of 30$\pm$5 meV from the measured trion binding energy shift. We obtain direct evidence for charge order linked to electronic Mott-Wigner states at filling factors $\nu$ = 1/3 and $\nu$ = 2/3 through the associated exciton Umklapp resonances.

6 + 11 pages, 4 + 15 figures

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Cited by in corpus (5)

• AC-Stark Spectroscopy of Interactions between Moiré Excitons and Polarons
• Purely electronic model for exciton-polaron formation in moiré heterostructures
• Manipulating Charge Distribution in Moiré Superlattices by Light
• Crystallizing electrons with artificially patterned lattices
• Electronic phonon-induced magnetism in moiré Mott-Wigner crystals