where G is the electrical conductance, G 0 = e 2 / ( π π ℏ ℏ ) ≈ ≈ 7.75 × × 10 − − 5 Ω Ω − − 1 is the conductance quantum, T n are the transmission eigenvalues of the channels, and the sum runs over all transport channels in the conductor. This formula is very simple and physically sensible: The conductance of a nanoscale conductor is given by the sum of all the transmission possibilities that an electron has when propagating with an energy equal to the chemical potential, E = μ μ .