Nanoscale Conductivity Imaging of Correlated Electronic States in WSe2/WS2 Moiré Superlattices

Abstract

We report the nanoscale conductivity imaging of correlated electronic states in angle-aligned WSe2/WS2 heterostructures using microwave impedance microscopy. The noncontact microwave probe allows us to observe the Mott insulating state with one hole per moiré unit cell that persists for temperatures up to 150 K, consistent with other characterization techniques. In addition, we identify for the first time a Mott insulating state at one electron per moiré unit cell. Appreciable inhomogeneity of the correlated states is directly visualized in the hetero-bilayer region, indicative of local disorders in the moiré superlattice potential or electrostatic doping. Our work provides important insights on 2D moiré systems down to the microscopic level.

12 Pages, 4 figures

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• Emergence of Superlattice Dirac Points in Graphene on Hexagonal Boron Nitride
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• Two-dimensional Kagome Materials: Theoretical Insights, Experimental Realizations, and Electronic Structures
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• Distinct moiré textures of in-plane electric polarizations for distinguishing moiré origins in homobilayers
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• Moiré Imaging in Twisted Bilayer Graphene Aligned on Hexagonal Boron Nitride
• Realization of independent contacts in barrier-separated InAs/GaSb quantum wells
• Interaction enhanced inter-site hoppings for holons and interlayer exciton insulators in moiré correlated insulators
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