Acoustic-phonon-mediated superconductivity in Bernal bilayer graphene

We present a systematic theory of acoustic-phonon-mediated superconductivity which incorporates Coulomb repulsion, explaining the recent experiment in Bernal bilayer graphene under a large displacement field. The acoustic-phonon mechanism predicts that s-wave spin-singlet and f-wave spin-triplet pairings are degenerate and dominant. Assuming a spin-polarized valley-unpolarized normal state, we obtain f-wave spin-triplet superconductivity with T-c similar to 20 mK near n(e) = -0.6 x 10(12) cm(-2) for hole doping, in approximate agreement with the experiment. We further predict the existence of superconductivity for larger doping in both electron-doped and hole-doped regimes. Our results indicate that the observed spin-triplet superconductivity in Bernal bilayer graphene arises from acoustic phonons.

Automated summary

This article presents a systematic theory of acoustic-phonon-mediated superconductivity that incorporates Coulomb repulsion and explains recent experiments in Bernal bilayer graphene. The theory predicts that s-wave spin-singlet and f-wave spin-triplet pairings are degenerate and dominant. The results indicate that the observed spin-triplet superconductivity in Bernal bilayer graphene arises from acoustic phonons.