We predict two topological superconducting phases in microscopic models arising from the Berry phase associated with the valley degree of freedom in gapped Dirac honeycomb systems. The first one is a topological helical spin-triplet superconductor with a nonzero center-of-mass momentum that does not break time-reversal symmetry. We also find a topological chiral-triplet superconductor with Chern number ±1 with equal-spin-pairing in one valley and opposite-spin-triplet pairing in the other valley. Our results are obtained for the Kane-Mele model in which we have explored the effect of three different interactions, onsite attraction U, nearest-neighbor density-density attraction V, and nearest-neighbor antiferromagnetic exchange J, within self-consistent Bogoliubov--de Gennes theory. Transition metal dichalcogenides and cold atom experiments are promising platforms to explore these phases.
@article{arxiv.1806.08795,
title = {Topological superconductivity in Dirac honeycomb systems},
author = {Kyungmin Lee and Tamaghna Hazra and Mohit Randeria and Nandini Trivedi},
journal= {arXiv preprint arXiv:1806.08795},
year = {2019}
}