Hierarchy of Symmetry Breaking Correlated Phases in Twisted Bilayer Graphene
Abstract
Twisted bilayer graphene (TBG) near the magic twist angle of ∼1.1° exhibits a rich phase diagram. However, the interplay between different phases and their dependence on twist angle is still elusive. Here, we explore the stability of various TBG phases and demonstrate that superconductivity near filling of two electrons per moiré unit cell alongside Fermi surface reconstructions, as well as entropy-driven high-temperature phase transitions and linear-in-T resistance occur over a range of twist angles which extends far beyond those exhibiting correlated insulating phases. In the vicinity of the magic angle, we also find a metallic phase that displays a hysteretic anomalous Hall effect and incipient Chern insulating behaviour. Such a metallic phase can be rationalized in terms of the interplay between interaction-driven deformations of TBG bands leading to Berry curvature redistribution and Fermi surface reconstruction. Our results provide an extensive perspective on the hierarchy of correlated phases in TBG as classified by their robustness against deviations from the magic angle or, equivalently, their electronic interaction requirements.
Additional Information
Attribution 4.0 International (CC BY 4.0). We acknowledge discussions with Cyprian Lewandowski, Jason Alicea, and Alex Thomson. This work has been primarily supported by the DOE-QIS program (DE-SC0019166) and NSF-CAREER (DMR-1753306). S.N-P. acknowledges support from the Sloan Foundation. G.R. and S.N.-P. also acknowledge the support of the Institute for Quantum Information and Matter, an NSF Physics Frontiers Center with support of the Gordon and Betty Moore Foundation through Grant GBMF1250; Y.P. acknowledges support from the startup fund from California State University, Northridge. F.v.O. is supported by Deutsche Forschungsgemeinschaft within CRC 183 (project C02) as well as the project TWISTGRAPH. Author Contribution: R.P. and Y.Z. performed the measurements, fabricated devices, and analyzed the data. H.P., Y.C., and H.K. helped with device fabrication and data analysis. Y. P. developed a theoretical model and performed model calculations in close collaboration with F.v.O. and G.R. K.W., and T.T. provides hBN crystals. S.N-P. supervised the project. R.P, Y.Z. Y.P., F.v.O. G.R. and S.N-P. wrote the manuscript with the input of other authors. Data availability: The data that support the findings of this study are available from the corresponding authors on reasonable request. Code availability: The code that support the findings of this study are available from the corresponding authors on reasonable request. The authors declare no competing interests.Attached Files
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Additional details
- Eprint ID
- 114894
- Resolver ID
- CaltechAUTHORS:20220524-180258498
- DE-SC0019166
- Department of Energy (DOE)
- DMR-1753306
- NSF
- Alfred P. Sloan Foundation
- Institute for Quantum Information and Matter (IQIM)
- GBMF1250
- Gordon and Betty Moore Foundation
- California State University, Northridge
- CRC 183
- Deutsche Forschungsgemeinschaft (DFG)
- Created
-
2022-05-24Created from EPrint's datestamp field
- Updated
-
2023-06-02Created from EPrint's last_modified field
- Caltech groups
- Institute for Quantum Information and Matter