• 文献标题:   Identification of superconducting pairing symmetry in twisted bilayer graphene using in-plane magnetic field and strain
  • 文献类型:   Article
  • 作  者:   WU FC, DAS SARMA S
  • 作者关键词:  
  • 出版物名称:   PHYSICAL REVIEW B
  • ISSN:   2469-9950 EI 2469-9969
  • 通讯作者地址:   Univ Maryland
  • 被引频次:   16
  • DOI:   10.1103/PhysRevB.99.220507
  • 出版年:   2019

▎ 摘  要

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.