Tensor network simulation of the Kitaev-Heisenberg model at finite temperature.

We investigate the Kitaev-Heisenberg (KH) model at finite temperature using the exact environment full update (eeFU), introduced in Phys. Rev. B 99, 035115 (2019), which represents purification of a thermal density matrix on an infinite hexagonal lattice by an infinite projected entangled pair state (iPEPS). We estimate critical temperatures for coupling constants in the stripy and the antiferromagnetic phase. They are an order of magnitude less than the couplings.