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Kagome Quantum Oscillations in Graphene Superlattices
Folkert K de Vries1, Sergey Slizovskiy2,3, Petar Tomić1
1Laboratory for Solid State Physics, ETH Zürich, Zürich CH-8093, Switzerland.
Nano Letters
|January 5, 2024
Summary
We found semiclassical precursors to quantum magneto-oscillations in graphene superlattices. These Aharonov-Bohm interference effects occur at low magnetic fields near Lifshitz transitions.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Quantum Mechanics
Background:
- Electronic spectra in solids under magnetic fields are typically analyzed using Landau levels and Hofstadter-butterfly-style Brown-Zak minibands.
- These phenomena are observed as magneto-oscillations in two-dimensional electron systems.
Purpose of the Study:
- To investigate the semiclassical origins of quantum magneto-oscillations in graphene superlattices.
- To identify precursors to these oscillations that appear at low magnetic fields and elevated temperatures.
Main Methods:
- Analysis of electronic spectra in graphene superlattices subjected to a magnetic field.
- Investigation of Aharonov-Bohm interference effects in electron wave trajectories.
- Characterization of kagome-shaped path networks related to Lifshitz transitions.
Main Results:
- Observed semiclassical precursors to quantum magneto-oscillations in graphene superlattices.
- These precursors manifest near Lifshitz transitions at low magnetic fields.
- The oscillations persist even at elevated temperatures.
Conclusions:
- The study reveals semiclassical origins of quantum magneto-oscillations in twistronic graphenes.
- Aharonov-Bohm interference in specific electron trajectories explains these observed phenomena.
- The findings provide insights into the behavior of electrons in moire superlattices near Lifshitz transitions.
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