The Landauer formula relates the conductance \( G \) of a conductor to its transmission coefficient \( T \) and the quantum of conductance \( G_0 \): \[ G = G_0 \sum T_i \] where \( G_0 = \frac{2e^2}{h} \approx 7.748 \times 10^{-5} \, \text{S} \) is the quantum of conductance, \( e \) is the electron charge, and \( h \) is Planck's constant. The sum is over all available transmission channels \( i \).
