Nano-photocurrent mapping of local electronic structure in twisted bilayer graphene
arXiv:2006.07431 · doi:10.1021/acs.nanolett.9b04637
Abstract
We report a combined nano-photocurrent and infrared nanoscopy study of twisted bilayer graphene (TBG) enabling access to the local electronic phenomena at length scales as short as 20 nm. We show that the photocurrent changes sign at carrier densities tracking the local superlattice density of states of TBG. We use this property to identify domains of varying local twist angle by local photo-thermoelectric effect. Consistent with the photocurrent study, infrared nano-imaging experiments reveal optical conductivity features dominated by twist-angle dependent interband transitions. Our results provide a fast and robust method for mapping the electronic structure of TBG and suggest that similar methods can be broadly applied to probe electronic inhomogeneities of moiré superlattices in other van der Waals heterostructures.
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Cited by in corpus (13)
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- Symmetry breaking and anomalous conductivity in a double moiré superlattice
- Visualizing bulk and edge photocurrent flow in anisotropic Weyl semimetals
- Deep learning analysis of polaritonic waves images
- Atomic configuration controlled photocurrent in van der Waals homostructures
- Theory of plasmonic edge states in chiral bilayer systems
- Nonlinear intensity dependence of photogalvanics and photoconductance induced by terahertz laser radiation in twisted bilayer graphene close to magic angle
- Infrared photoresistance as a sensitive probe of electronic transport in twisted bilayer graphene
- Cascades in transport and optical conductivity of Twisted Bilayer Graphene
- Interaction-mitigated Landau damping
- Optical vortex probe of loop-current chirality in moiré materials