Before revision: equation {\kappa \over \sigma} = LT, equation equation L = {\pi^2 k_B^2 \over 3e^2}.
After revision: The thermal conductance quantum, also called as quantized thermal conductance, maybe understood from the Wiedemann-Franz law, which show thatwhere L is a universal constant,equation {\kappa \over \sigma} = LT, equation equation L = {\pi^2 k_B^2 \over 3e^2}.