6533b7cffe1ef96bd12587ec
RESEARCH PRODUCT
Mean-field theory for superconductivity in twisted bilayer graphene
Teemu PeltonenRisto OjajärviTero Heikkiläsubject
superconducting phase transitionsuperconducting gapsuprajohtavuusCondensed Matter::Superconductivitygrafeenisuperconducting order parameterdescription
Recent experiments show how a bilayer graphene twisted around a certain magic angle becomes superconducting as it is doped into a region with approximate flat bands. We investigate the mean-field s-wave superconducting state in such a system and show how the state evolves as the twist angle is tuned, and as a function of the doping level. We argue that part of the experimental findings could well be understood to result from an attractive electron-electron interaction mediated by electron-phonon coupling, but the flat-band nature of the excitation spectrum also makes the superconductivity quite unusual. For example, as the flat-band states are highly localized around certain spots in the structure, also the superconducting order parameter becomes strongly inhomogeneous. peerReviewed
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2018-01-01 |