Abstract
We employ a functional renormalization group approach to ascertain the pairing mechanism and symmetry of the superconducting phase observed in rhombohedral trilayer graphene. Superconductivity in this system occurs in a regime of carrier density and displacement field with a weakly distorted annular Fermi sea. We find that repulsive Coulomb interactions can induce electron pairing on the Fermi surface by taking advantage of momentum-space structure associated with the finite width of the Fermi sea annulus. The degeneracy between spin-singlet and spin-triplet pairing is lifted by valley-exchange interactions that strengthen under the RG flow and develop nontrivial momentum-space structure. We find that the leading pairing instability is d-wave-like and spin singlet, and that the theoretical phase diagram versus carrier density and displacement field agrees qualitatively with experiment.
| Original language | English |
|---|---|
| Article number | 146001 |
| Journal | Physical Review Letters |
| Volume | 130 |
| Issue number | 14 |
| DOIs | |
| State | Published - Apr 7 2023 |
Bibliographical note
Publisher Copyright:© 2023 American Physical Society.
Funding
The authors are grateful for helpful interactions with Andrea F. Young, Haoxin Zhou, and Jihang Zhu. This work was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, under Award No. DE-SC0022106. The work done at LANL was carried out under the auspices of the U.S. DOE NNSA under Contract No. 89233218CNA000001 through the LDRD Program. T. M. R. W. is grateful for the financial support from the Swiss National Science Foundation (Postdoc.Mobility Grant No. 203152). Numerical calculations were performed using supercomputing resources at the Texas Advanced Computing Center (TACC).
| Funders | Funder number |
|---|---|
| U.S. Department of Energy EPSCoR | |
| Office of Science Programs | |
| DOE Basic Energy Sciences | DE-SC0022106 |
| DOE Basic Energy Sciences | |
| National Nuclear Security Administration | 89233218CNA000001 |
| National Nuclear Security Administration | |
| Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung | 203152 |
| Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung |
ASJC Scopus subject areas
- General Physics and Astronomy