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Updated: Oct 6, 2025
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Scalable Quantum Integrated Circuits on Superconducting Two-Dimensional Electron Gas Platform
Published on: August 2, 2019
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Crossover between strongly coupled and weakly coupled exciton superfluids.
Xiaomeng Liu1, J I A Li2, Kenji Watanabe3
1Department of Physics, Harvard University, Cambridge, MA 02138, USA.
Science (New York, N.Y.)
|January 13, 2022
Summary
Researchers tuned quantum condensates in graphene by controlling electron-hole pairing. This work establishes graphene double layers as a model system for studying quantum condensate phases in solids.
Area of Science:
- Condensed Matter Physics
- Quantum Materials
- Superconductivity
Background:
- Superconductivity and superfluidity arise from fermion pair condensation.
- Tuning pairing strength in electronic systems is experimentally difficult.
- Graphene systems offer unique platforms for exploring quantum phenomena.
Purpose of the Study:
- To investigate the tunability of quantum condensates in graphene double layers.
- To explore the crossover between different bosonic quantum condensate phases.
- To establish a model system for studying pairing strength variations.
Main Methods:
- Fabrication of graphene double layers separated by an atomically thin insulator.
- Application of magnetic fields to couple electrons and holes across the barrier.
- Utilizing temperature-dependent Coulomb drag and counterflow current measurements.
- Tuning effective layer separation to control pairing strength.
Main Results:
- Formation of bound magneto-exciton condensates in graphene.
- Continuous tuning of condensate pairing strength from weak to strong coupling.
- Observation of the entire phase diagram of the magneto-exciton condensate.
- Demonstration of tunable quantum condensation in a solid-state system.
Conclusions:
- Graphene double layers provide a versatile platform for studying quantum condensates.
- Magneto-exciton condensates in graphene enable exploration of the weak-to-strong coupling crossover.
- This research advances the understanding of quantum phase transitions in solid-state systems.
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