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Photoinduced Metal-to-Insulator Transitions in 2D Moiré Devices.
Yiliu Li1, Esteban Rojas-Gatjens1, Yinjie Guo2
1Columbia University, Department of Chemistry, New York, New York 10027, USA.
Physical Review Letters
|June 7, 2026
Summary
Researchers demonstrate an ultrafast metal-to-insulator transition in van der Waals heterostructures. This discovery enables the control of metastable electronic phases using photoexcitation, opening new avenues in quantum matter research.
Area of Science:
- Condensed Matter Physics
- Quantum Materials Science
- Materials Chemistry
Background:
- Photoexcitation is a known method for controlling quantum matter and accessing non-equilibrium states.
- Previous studies focused on insulator-to-metal transitions; the reverse, metal-to-insulator transition, remained unobserved.
- Metastable phases are crucial for understanding exotic electronic behaviors.
Purpose of the Study:
- To investigate the possibility of an ultrafast metal-to-insulator transition in van der Waals (vdW) heterostructures.
- To explore the creation and characteristics of metastable correlated insulating states.
- To establish a novel mechanism for controlling electronic phases in vdW heterostructures.
Main Methods:
- Utilized gate-doped WS_{2}/WSe_{2} and WSe_{2}/WSe_{2} moiré devices.
- Employed photothermionic hole injection from graphite gates for photoexcitation.
- Measured the resulting electronic phase transitions and their lifetimes.
Main Results:
- Achieved an ultrafast metal-to-insulator transition.
- Created metastable correlated insulating states with lifetimes exceeding microseconds.
- Demonstrated the effectiveness of photothermionic injection for phase control.
Conclusions:
- Established a new pathway for controlling correlated electronic phases in vdW heterostructures.
- The observed metal-to-insulator transition provides a method for generating metastable states.
- This work advances the understanding and manipulation of quantum matter far from equilibrium.
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