Spin-triplet $f$-wave pairing in twisted bilayer graphene near 1/4 filling

TL;DR

This study uses a two-orbital Hubbard model and functional renormalization group theory to reveal spin-triplet f-wave pairing in twisted bilayer graphene near 1/4 filling, highlighting the role of Hund's coupling and spin fluctuations.

Contribution

It demonstrates the emergence of spin-triplet f-wave pairing in twisted bilayer graphene using a two-orbital Hubbard model and advanced renormalization techniques, a novel insight into pairing mechanisms.

Findings

Spin-triplet f-wave pairing is found near 1/4 filling.

Pairing is linked to Hund's rule coupling and incommensurate spin fluctuations.

Results apply across weak to moderate coupling regimes.

Abstract

We investigate the twisted bilayer graphene by a two-orbital Hubbard model on the honeycomb lattice. The model is studied near 1/4 band filling by using the singular-mode functional renormalization group theory. Spin-triplet $f$-wave pairing is found from weak to moderate coupling limit of the local interactions, and is associated with the Hund's rule coupling and incommensurate spin fluctuations at moderate momenta.