Measuring local moiré lattice heterogeneity of twisted bilayer graphene
| Autor: | Vincent Stalman, Tjerk Benschop, Tobias A. de Jong, Petr Stepanov, Xiaobo Lu, Milan P. Allan, Sense Jan van der Molen, Dmitri K. Efetov |
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| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
Physics
Condensed Matter - Mesoscale and Nanoscale Physics Condensed matter physics moiré superlattice graphene Lattice (group) 02 engineering and technology Electronic structure 021001 nanoscience & nanotechnology 01 natural sciences Measure (mathematics) Condensed Matter - Strongly Correlated Electrons 0103 physical sciences scanning tunneling microscopy Twist angle twisted bilayer graphene 010306 general physics 0210 nano-technology Anisotropy Bilayer graphene |
| Zdroj: | Physical Review Research, 3(1), 013153 |
| Popis: | We introduce a new method to continuously map inhomogeneities of a moir\'e lattice and apply it to large-area topographic images we measure on open-device twisted bilayer graphene (TBG). We show that the variation in the twist angle of a TBG device, which is frequently conjectured to be the reason for differences between devices with a supposed similar twist angle, is about 0.08{\deg} around the average of 2.02{\deg} over areas of several hundred nm, comparable to devices encapsulated between hBN slabs. We distinguish between an effective twist angle and local anisotropy and relate the latter to heterostrain. Our results imply that for our devices, twist angle heterogeneity has a roughly equal effect to the electronic structure as local strain. The method introduced here is applicable to results from different imaging techniques, and on different moir\'e materials. Comment: 4 figures in main text. Supporting info included |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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