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Synthetic Semimetals with van der Waals Interfaces
Bojja Aditya Reddy1,2, Evgeniy Ponomarev1,2, Ignacio Gutiérrez-Lezama1,2
1Department of Quantum Matter Physics , University of Geneva , 24 Quai Ernest Ansermet , CH-1211 Geneva , Switzerland.
Nano Letters
|December 25, 2019
Summary
Researchers created synthetic semimetals using van der Waals (vdW) heterostructures of WSe2 and SnSe2. These novel materials exhibit unique electronic properties and open doors for engineering advanced quantum states.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Nanotechnology
Background:
- Van der Waals (vdW) heterostructures offer a route to engineer artificial materials with tailored electronic properties.
- Semimetals, materials with unique electronic band structures, are of great interest for fundamental research and potential applications.
Purpose of the Study:
- To realize synthetic semimetals using vdW interfaces formed by two different semiconductors.
- To demonstrate and characterize the semimetallic state in these engineered vdW heterostructures.
Main Methods:
- Assembly of vdW heterostructures using WSe2 and SnSe2 mono- and multilayers.
- Transport experiments, including gate sweeps in ionic liquid gated devices.
- Hall effect measurements at varying gate voltages and temperatures.
- Spectroscopic techniques for quantitative band overlap determination.
Main Results:
- Demonstrated semimetallicity in WSe2/SnSe2 vdW interfaces through transport measurements.
- Observed finite minimum conductance and quantitative band overlap in gate-tuned devices.
- Detected coexistence of electrons and holes via Hall effect measurements.
- Achieved low-temperature metallic conductivity at interfaces of initially insulating materials.
Conclusions:
- Successfully implemented a novel semimetallic state in vdW interfaces.
- These findings pave the way for engineering topological and excitonic insulating states using vdW heterostructures.
- Highlights the potential of vdW engineering for creating new states of matter.
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