Hi everyone. I have to say I never get satisfied with introductory explanations of how electric phenomena occurs. Specifically, I would like to know how Quantum Mechanics explain the raise of a electric current and especially what makes a resistor being (maybe) the most dissipative element in a circuit. I guess we would need to know about how the atoms are interacting with each other as with the free (less bounded in QM language) electrons as well in a specific material to answer these questions. But that would then make it very hard to explain these things using Quantum Mechanics.