|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|
|Date Published||JUN 25|
|Type of Article||Article|
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.