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Optimized Fabrication Procedure for High-Quality Graphene-based Moiré Superlattice Devices
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1D Electronic Flat Bands in Untwisted Moiré Superlattices
Yafei Li1, Qing Yuan1, Deping Guo2,3
1School of Physics and Technology and Key Laboratory of Artificial Micro- and Nano-Structures of Ministry of Education, Wuhan University, Wuhan, 430072, P. R. China.
Advanced Materials (Deerfield Beach, Fla.)
|April 14, 2023
Summary
Researchers discovered one-dimensional electronic flat bands (1D-EFBs) in untwisted bismuth superlattices on tin selenide. This finding offers a scalable method for creating 1D-EFBs without complex twisting techniques.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Surface Science
Background:
- Two-dimensional electronic flat bands (2D-EFBs) are known in van der Waals (vdW) superlattices.
- One-dimensional electronic flat bands (1D-EFBs) have been observed in twisted vdW bilayers, but are experimentally challenging to realize in untwisted systems.
- Scalable fabrication of 1D-EFBs in untwisted vdW layers is highly desired.
Purpose of the Study:
- To report the discovery of 1D-EFBs in an untwisted, in situ-grown two atomic-layer Bi(110) superlattice on an SnSe(001) substrate.
- To investigate the mechanism behind the formation of these 1D-EFBs.
- To propose a general strategy for engineering 1D-EFBs in untwisted vdW systems.
Main Methods:
- Scanning probe microscopy measurements
- Density functional theory (DFT) calculations
- In situ growth of Bi(110) on SnSe(001)
Main Results:
- Discovery of 1D-EFBs in an untwisted Bi(110)/SnSe(001) heterostructure.
- Identification of 1D buckling reversal regions (BRRs) induced by epitaxial lattice mismatch.
- Spatial correlation between BRRs and the emergence of 1D-EFBs, with electronic states isolated along the armchair (AC) direction and localized along the zigzag (ZZ) direction due to quantum interference.
Conclusions:
- The study demonstrates the feasibility of achieving 1D-EFBs in untwisted vdW superlattices.
- Lattice mismatch in carefully chosen rectangular vdW heterostructures is a viable route to engineer 1D-EFBs.
- This work presents a generalized strategy for fabricating 1D-EFBs, enhancing scalability and potential applications.
Keywords:
1D electronic flat bandsbuckling reversaldensity functional theoryscanning probe microscopyuntwisted moiré superlatticesMore Related Videos
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