Title | Identification of superconducting pairing symmetry in twisted bilayer graphene using in-plane magnetic field and strain |
Publication Type | Journal Article |
Year of Publication | 2019 |
Authors | F. Wu, and S. Das Sarma |
Journal | Phys. Rev. B |
Volume | 99 |
Pagination | 220507 |
Date Published | JUN 25 |
Type of Article | Article |
ISSN | 2469-9950 |
Abstract | We show how the pairing symmetry of superconducting states in twisted bilayer graphene can be experimentally identified by theoretically studying effects of externally applied in-plane magnetic field and strain. In the low-field regime, superconducting critical temperature T-c is suppressed by in-plane magnetic field B-parallel to in singlet channels, but is enhanced by weak B-parallel to in triplet channels, providing an important distinction. The in-plane angular dependence of the critical B-parallel to,B-c has a sixfold rotational symmetry, which is broken when strain is present. We show that anisotropy in B-parallel to,B-c generated by strain can be similar for s- and d-wave channels in moire superlattices. The d-wave state is pinned to be nematic by strain and consequently gapless, which is distinguishable from the fully gapped s-wave state by tunneling gap measurements. |
DOI | 10.1103/PhysRevB.99.220507 |