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Electrically tunable Feshbach resonances in twisted bilayer semiconductors
Ido Schwartz1,2, Yuya Shimazaki1,3, Clemens Kuhlenkamp1,4,5
1Institute for Quantum Electronics, ETH Zürich, CH-8093 Zürich, Switzerland.
Science (New York, N.Y.)
|October 14, 2021
Summary
Researchers used MoSe2 bilayers to control interactions between excitons and holes. This work demonstrates electric field control over quantum phenomena, paving the way for tunable Bose-Fermi mixtures.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Quantum Optics
Background:
- Moiré superlattices in transition metal dichalcogenide bilayers are platforms for studying strong correlations using optical spectroscopy.
- Mott-Wigner physics is observed, driven by periodic potential and Coulomb interactions, but lacks hybridization of electronic states due to absent tunnel coupling.
- A classical layer degree of freedom has persisted in these systems.
Purpose of the Study:
- To investigate a MoSe2 homobilayer structure for electric field-controlled manipulation of electronic states.
- To explore the role of interlayer coherent tunneling in controlling ground-state hole-layer pseudospin.
- To achieve tunable interactions between excitons and holes in different layers.
Main Methods:
- Fabrication of a MoSe2 homobilayer structure.
- Utilizing interlayer coherent tunneling for quantum state manipulation.
- Employing optical spectroscopy to probe exciton-hole scattering.
- Applying electric fields to tune interactions.
Main Results:
- Demonstrated electric field-controlled manipulation and measurement of ground-state hole-layer pseudospin.
- Observed an electrically tunable two-dimensional Feshbach resonance in exciton-hole scattering.
- Showcased control over interaction strength between excitons and holes in distinct layers.
Conclusions:
- The study successfully manipulated quantum states in MoSe2 bilayers using electric fields.
- The observed Feshbach resonance provides a mechanism for tuning exciton-hole interactions.
- These findings may enable the creation of degenerate Bose-Fermi mixtures with controllable interactions.
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