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Tunable vacuum-field control of fractional and integer quantum Hall phases
Josefine Enkner1,2, Lorenzo Graziotto3,4, Dalin Boriçi5
1Institute for Quantum Electronics, ETH Zürich, Zürich, Switzerland. enknerj@phys.ethz.ch.
Nature
|May 14, 2025
Summary
Researchers explored how vacuum fields influence quantum Hall systems. They found that coupling a 2D electron gas to cavity vacuum fields can alter electronic correlations, impacting quantum materials and device engineering.
Area of Science:
- Condensed matter physics
- Quantum mechanics
- Quantum materials science
Background:
- Vacuum fields, though small in free-space atomic physics, are crucial in low-dimensional solid-state systems.
- The interplay between electronic correlations and quantum electrodynamics (QED) is key in advanced materials.
- High-mobility two-dimensional electron gases (2DEGs) in the quantum Hall regime are ideal for studying vacuum field effects.
Purpose of the Study:
- To investigate the impact of vacuum electromagnetic fields on strongly correlated electronic states in 2DEGs.
- To explore how adjusting the coupling strength between 2DEGs and cavity vacuum fields affects quantum Hall phenomena.
- To uncover new mechanisms for manipulating quantum phases in low-dimensional materials.
Main Methods:
- Utilizing a hovering split-ring resonator to control coupling between 2D electron gases and vacuum fields.
- Observing changes in exchange splitting at odd-integer filling factors.
- Measuring enhancements in fractional quantum Hall gaps at specific filling factors (4/3, 5/3, 7/5).
Main Results:
- A significant reduction in exchange splitting was observed at odd-integer filling factors.
- Enhancements in fractional quantum Hall gaps were detected at filling factors 4/3, 5/3, and 7/5.
- Theoretical analysis confirmed an effective long-range attractive interaction mediated by virtual cavity photons.
Conclusions:
- Cavity vacuum fields can reshape electronic correlations in quantum Hall systems.
- This provides a novel mechanism for manipulating correlated quantum phases.
- The findings open avenues for engineering tailored many-body interactions in compact quantum devices.
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