Tuesday, July 30, 2013

1307.7426 (Keiji Saito et al.)

Kondo signature in heat transfer via a local two-state system    [PDF]

Keiji Saito, Takeo Kato
We study the Kondo effect in heat transport via a local two-state system. This system is described by the spin-boson Hamiltonian with Ohmic dissipation, which can be mapped onto the Kondo model with anisotropic exchange coupling. We calculate thermal conductance by the Monte Carlo method based on the exact formula. Thermal conductance has a scaling form $\kappa = (k_B^2 T_K/\hbar) f(\alpha,T/T_K)$, where $T_K$ and $\alpha$ indicate the Kondo temperature and dimensionless coupling strength, respectively. Below $T_K$, conductance follows the universal $T^3$-law, showing nontrivial enhancement. Above $T_K$, strong suppression of incoherent tunneling is indicated in coupling dependence of conductance. Similarities to the Kondo signature in electric transport are discussed.
View original: http://arxiv.org/abs/1307.7426

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