Lawrence Berkeley National Laboratory
Nematic superconductivity stabilized by density wave fluctuations: Possible application to twisted bilayer graphene
- Author(s): Kozii, Vladyslav
- Isobe, Hiroki
- Venderbos, Jörn WF
- Fu, Liang
- et al.
Published Web Locationhttps://doi.org/10.1103/physrevb.99.144507
© 2019 American Physical Society. Nematic superconductors possess unconventional superconducting order parameters that spontaneously break rotational symmetry of the underlying crystal. In this work we propose a mechanism for nematic superconductivity stabilized by strong density wave fluctuations in two dimensions. While the weak-coupling theory finds the fully gapped chiral state to be energetically stable, we show that strong density wave fluctuations result in an additional contribution to the free energy of a superconductor with multicomponent order parameters, which generally favors nematic superconductivity. Our theory sheds light on the recent observation of rotational symmetry breaking in the superconducting state of twisted bilayer graphene.