Thermal Hall Conductivity in Superconducting Phase on Kagome Lattice

Abstract

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, which 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. arXiv:1808.01765v2 [cond-mat.supr-con]

Γ valley transition metal dichalcogenide moiré bands

“…Since all models have bandwidths that can be adjusted simply by varying twist angles or by applying pressure, they provide an enticing platform to study the exotic properties of strongly correlation physics on the honeycomb lattice (46)(47)(48)(49)(50). Furthermore, by inducing spin-orbit coupling with gate electric fields or by proximity, all bands can exhibit topologically nontrivial states (51)(52)(53)(54). Finally, the Hamiltonian presented here can be easily generalized to include gate electric fields or to describe Γ α homobilayers and heterobilayers by simply relaxing the (φs = 0, π) constraint imposed by the emergent D6 symmetry.…”

$Γ$-Valley Transition-Metal-Dichalcogenide Moirè Bands

“…Since all models have bandwidths that can be adjusted simply by varying twist angles or by applying pressure, they provide an enticing platform to study the exotic properties of strongly correlation physics on the honeycomb lattice [48][49][50][51][52]. Furthermore, by inducing spin-orbit coupling with gate electric fields or by proximity, all bands can exhibit topologically non-trivial states [53][54][55][56]. Finally, the Hamiltonian presented here can be easily generalized to describe Γ α-homobilayers or heterobilayers by simply relaxing the (φ s = 0, π) constraint imposed by the emergent D 6 symmetry.…”

Real-space calculation of thermal Hall effects in strained and disordered kagome ferromagnets

“…There have been numerous studies on MHE in various materials [11][12][13][14][15][16][17], among which the Kagome lattice, a frustrated spin structure, has attracted great research interest due to its exotic properties. It has been revealed thermal conductivity in kagome ferromagnets is linearly dependent on temperature within the weak-magnetic-field and low-temperature limits [5].…”