One-dimensional flat bands in twisted bilayer germanium selenide.
D M Kennes1,2, L Xian3, M Claassen4
1Institut für Theorie der Statistischen Physik, RWTH Aachen University and JARA-Fundamentals of Future Information Technology, 52056, Aachen, Germany. Dante.Kennes@rwth-aachen.de.
Nature Communications
|March 1, 2020
Summary
Twisted bilayer germanium selenide (GeSe) unexpectedly forms an effective one-dimensional system, unlike other moiré materials. This discovery offers a new platform for studying strongly correlated physics in low-dimensional systems.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Quantum Mechanics
Background:
- Recent experiments show flat energy bands in twisted few-layer materials due to electron interactions.
- This opens avenues for exploring strongly correlated physics in two-dimensional (2D) systems.
Purpose of the Study:
- To investigate the electronic properties of twisted bilayer germanium selenide (GeSe).
- To explore the emergence of low-dimensional behavior in moiré systems.
Main Methods:
- Large-scale ab initio simulations.
- Numerically exact strong correlation approaches.
Main Results:
- An effective one-dimensional (1D) system emerges in twisted bilayer GeSe.
- This behavior is distinct from previously studied moiré systems.
- The system allows for studying collective excitations in 1D.
Conclusions:
- Twisted bilayer GeSe provides a unique platform for studying 1D strongly correlated physics.
- It enables controlled investigation of the 2D to 1D dimensional crossover by tuning the twist angle.
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