Saved in:
| Main Authors: | , , , , , , , , |
|---|---|
| Format: | Preprint |
| Published: |
2024
|
| Subjects: | |
| Online Access: | https://arxiv.org/abs/2406.02195 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1866929373090676736 |
|---|---|
| author | Chiodini, Stefano Venturi, Giacomo Kerfoot, James Zhang, Jincan Alexeev, Evgeny M. Taniguchi, Takashi Watanabe, Kenji Ferrari, Andrea C. Ambrosio, Antonio |
| author_facet | Chiodini, Stefano Venturi, Giacomo Kerfoot, James Zhang, Jincan Alexeev, Evgeny M. Taniguchi, Takashi Watanabe, Kenji Ferrari, Andrea C. Ambrosio, Antonio |
| contents | In twisted layered materials (t-LMs), an inter-layer rotation can break inversion symmetry and create an interfacial array of staggered out-of-plane polarization due to AB/BA stacking registries. This symmetry breaking can also trigger the formation of edge in-plane polarizations localized along the perimeter of AB/BA regions (i.e., saddle point domains). However, a comprehensive experimental investigation of these features is still lacking. Here, we use piezo force microscopy to probe the electromechanical behavior of twisted hexagonal boron nitride (t-hBN). For a parallel stacking alignment of t-hBN, we reveal very narrow (width ~ 20 nm) saddle point polarizations, which we also measure in the anti-parallel configuration. These localized polarizations can still be found on a multiply-stacked t-hBN structure, determining the formation of a double moiré. We also visualize a t-hBN moiré superlattice in the topography maps with atomic force microscopy, related to the strain accumulated at the saddle point domains. Our findings imply that polarizations in t-hBN do not only point in the out-of-plane direction, but also show an in-plane component, giving rise to a much more complex 3D polarization field. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2406_02195 |
| institution | arXiv |
| publishDate | 2024 |
| record_format | arxiv |
| spellingShingle | Electromechanical response of saddle points in twisted hBN moiré superlattices Chiodini, Stefano Venturi, Giacomo Kerfoot, James Zhang, Jincan Alexeev, Evgeny M. Taniguchi, Takashi Watanabe, Kenji Ferrari, Andrea C. Ambrosio, Antonio Materials Science In twisted layered materials (t-LMs), an inter-layer rotation can break inversion symmetry and create an interfacial array of staggered out-of-plane polarization due to AB/BA stacking registries. This symmetry breaking can also trigger the formation of edge in-plane polarizations localized along the perimeter of AB/BA regions (i.e., saddle point domains). However, a comprehensive experimental investigation of these features is still lacking. Here, we use piezo force microscopy to probe the electromechanical behavior of twisted hexagonal boron nitride (t-hBN). For a parallel stacking alignment of t-hBN, we reveal very narrow (width ~ 20 nm) saddle point polarizations, which we also measure in the anti-parallel configuration. These localized polarizations can still be found on a multiply-stacked t-hBN structure, determining the formation of a double moiré. We also visualize a t-hBN moiré superlattice in the topography maps with atomic force microscopy, related to the strain accumulated at the saddle point domains. Our findings imply that polarizations in t-hBN do not only point in the out-of-plane direction, but also show an in-plane component, giving rise to a much more complex 3D polarization field. |
| title | Electromechanical response of saddle points in twisted hBN moiré superlattices |
| topic | Materials Science |
| url | https://arxiv.org/abs/2406.02195 |