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Evidence for electron-hole crystals in a Mott insulator.
Zhizhan Qiu1, Yixuan Han2, Keian Noori1,3
1Institute for Functional Intelligent Materials, National University of Singapore, Singapore, Singapore.
Researchers discovered imbalanced electron-hole crystals in doped Mott insulators like α-RuCl3 using graphene doping. This finding advances the search for exotic quantum states and correlated bosonic states in materials.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Quantum Mechanics
Background:
- Correlated electron and hole crystals can host quantum excitonic states.
- These states are crucial for understanding phenomena like counterflow superfluidity and topological orders.
Purpose of the Study:
- To investigate the formation and characteristics of imbalanced electron-hole crystals in a doped Mott insulator.
- To visualize the spatial arrangement and transitions of these charge crystals.
Main Methods:
- Utilized gate-tunable van der Waals doping with graphene on α-RuCl3.
- Employed scanning tunnelling microscopy for real-space imaging of charge ordering.
Main Results:
- Observed two distinct charge orderings attributed to a hole crystal and an electron crystal.
- Directly visualized a gate-induced transition between these electron-hole crystal states.
- Identified correlation-driven formation of a honeycomb hole crystal and a rotational-symmetry-breaking electron crystal.
Conclusions:
- Provided evidence for imbalanced electron-hole crystals in doped Mott insulators.
- Demonstrated the potential for creating and visualizing novel correlated charge states.
- Opened new avenues for exploring correlated bosonic states in strongly correlated materials.
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