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Optimized Fabrication Procedure for High-Quality Graphene-based Moiré Superlattice Devices
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Classifying superconductivity in Moiré graphene superlattices
E F Talantsev1,2, R C Mataira3, W P Crump3,4,5
1M.N. Miheev Institute of Metal Physics, Ural Branch, Russian Academy of Sciences, 18, S. Kovalevskoy St., Ekaterinburg, 620108, Russia. evgeny.talantsev@imp.uran.ru.
Scientific Reports
|January 16, 2020
Summary
Superconductivity in twisted bilayer graphene shows dominant s-wave and p-wave pairing symmetries. Further experiments are needed to distinguish between these symmetries and confirm two-band superconductivity in these 2D materials.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Superconductivity
Background:
- Superconductivity has been observed in twisted bilayer graphene (TBG) forming Moiré superlattices.
- Characterizing the superconducting state in these 2D materials is crucial for understanding their fundamental properties.
Purpose of the Study:
- Investigate the pairing symmetry of the superconducting state in TBG.
- Analyze superconductivity in TBG twisted at specific angles (1.05°, 1.10°, 1.16°) and doping levels.
Main Methods:
- Analysis of the temperature dependence of the upper critical magnetic field (Bc2(T)).
- Analysis of the self-field critical current (Jc(sf,T)).
- Application of models based on phonon-mediated Bardeen-Cooper-Schrieffer (BCS) theory for various gap symmetries (s-, d-, p-, and d+id-wave).
Main Results:
- Extracted superconducting parameters suggest that s-wave and a specific type of p-wave symmetries are likely dominant.
- The study considered single- and two-band superconductivity models.
Conclusions:
- The dominant pairing symmetries in TBG Moiré superlattices are likely s-wave and a specific p-wave.
- Distinguishing between s-wave and p-wave symmetries, and confirming two-band superconductivity, requires additional experimental data.
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