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Superstructure-Induced Splitting of Dirac Cones in Silicene
Baojie Feng1,2, Hui Zhou1,2, Ya Feng3,4
1Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
Physical Review Letters
|May 31, 2019
Summary
Researchers investigated Dirac cones in silicene on silver, revealing they originate from silicene
Area of Science:
- Condensed Matter Physics
- Materials Science
- Surface Science
Background:
- Atomic scale engineering of 2D materials offers potential for novel devices.
- External periodic potentials can tune electronic band structures.
- The (3×3)-silicene/Ag(111) system exhibits substrate-induced modulations.
Purpose of the Study:
- To clarify the origin of six Dirac cone pairs observed at the Brillouin zone boundary of Ag(111) in the (3×3)-silicene/Ag(111) system.
- To understand how substrate-overlayer interactions influence the electronic band structure of silicene.
Main Methods:
- Linear dichroism angle-resolved photoemission spectroscopy (LDARPES).
- Tight-binding model calculations.
- First-principles electronic structure calculations.
Main Results:
- The observed Dirac cones primarily originate from the K (K') points of free-standing silicene.
- External periodic potentials, arising from substrate-overlayer interactions, split the Dirac cones of silicene.
- Confirmation of the origin of Dirac cones in the (3×3)-silicene/Ag(111) system.
Conclusions:
- The study elucidates the source of Dirac cones in the (3×3)-silicene/Ag(111) interface.
- Provides a method for manipulating the electronic structures of 2D materials through controlled interactions.
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