Thermal plasmons and transport coefficients for pseudospin-1 dice lattices

Closed-form analytic expressions have been derived for the dynamic polarizability of the 2D pseudospin-1 dice lattices with a Berry phase for arbitrary frequency and wave vector. These calculations generalize previously reported results (J. D. Malcolm and E. J. Nicol, Phys. Rev. B { \bf 93}, 165433 (2016)). The plasmon dispersion relations at finite temperature for the dice lattice are compared with those of graphene to determine the role played by the presence of an additional flat subband. We also calculated the corresponding temeprature-depedent Boltzmann concuctivity in the relaxation-time approximation.