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Quantum-Confined Lifshitz Transition on Weyl Semimetal Td-MoTe2
Hyunjin Jung1,2, Kyung-Hwan Jin1,3, Minki Sung1,2
1Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science, Pohang 37673, Republic of Korea.
Potassium adsorption on Weyl semimetal Td-MoTe2 creates a 2D electron gas and quantum-confined Lifshitz transition. This surface modification alters electronic properties, paving the way for novel heterojunctions in van der Waals materials.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Surface Science
Background:
- Alkali atom adsorption is key for tuning electronic properties, especially in 2D materials.
- Effects on semimetallic systems are less understood compared to semiconductors.
- Controlling surface electronic states is crucial for advanced material applications.
Purpose of the Study:
- Investigate alkali adsorption effects on Weyl semimetals.
- Explore the creation of 2D electron gas and quantum confinement.
- Uncover the mechanism of Lifshitz transitions in these systems.
Main Methods:
- Angle-resolved photoemission spectroscopy (ARPES) for electronic structure.
- Density functional theory (DFT) calculations for theoretical insights.
- Surface modification via potassium adsorption on Td-MoTe2.
Main Results:
- Potassium adsorption induces a 2D electron gas on Td-MoTe2.
- Strong surface band bending and quantum confinement observed in the topmost layer.
- A quantum-confined Lifshitz transition occurs, creating a metallic surface state distinct from the bulk.
Conclusions:
- Alkali adsorption effectively modifies Weyl semimetal surface states.
- The findings enable the creation of electronic heterojunctions in van der Waals semimetals.
- This work provides a pathway for designing novel electronic devices based on 2D materials.
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