Before revision: Datta, Electronic Transport in Mesoscopic Systems, Cambridge University Press, 1995, Derivation In a 1D wire, connecting two reservoirs of potential and adiabatically: The density of states is , where the factor 2 comes from electron spin degeneracy, is Planck's constant, and is the electron velocity.
After revision: The ratio between the conductance quantum and thequantum capacitanceDatta, Electronic Transport in Mesoscopic Systems, Cambridge University Press, 1995, Derivation In a 1D wire, connecting two reservoirs of potential and adiabatically: The density of states is , where the factor 2 comes from electron spin degeneracy, is Planck's constant, and is the electron velocity.