Thermal Hall Conductivity in Superconducting Phase on Kagome Lattice
Shoma Iimura, Yoshiki Imai
2018
Journal of the Physical Society of Japan
Motivated by a previous "sd^2-graphene" study, the pairing symmetry in the superconducting state and the thermal Hall conductivity are investigated by a self-consistent Bogoliubov--de Gennes approach on the kagome lattice with intrinsic spin-orbit coupling near van Hove fillings. While the topologically trivial state with broken time-reversal symmetry appears in the absence of spin-orbit coupling, the highest flat band becomes dispersive with a hexagonal symmetry due to spin-orbit coupling,
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... h leads to a topological superconducting state. Since the thermal Hall conductivity in the low-temperature limit is associated with the topological property of time-reversal symmetry breaking superconductors, we study its temperature dependence near van Hove fillings. In particular, the pairing symmetry in the highest flat band is sensitive to the amplitudes of spin-orbit coupling and the attractive interaction, which is reflected remarkably in the thermal Hall conductivity. The obtained result may enable us to investigate the stable superconducting state on the kagome lattice.
doi:10.7566/jpsj.87.094715
fatcat:rx4pulzvdbdytmey7umnz4subm