The discussion revolves around the derivation of Ohm's law from a quantum mechanical perspective, particularly in relation to various models of electron conduction. Participants explore the classical Drude model and its limitations, as well as more advanced quantum models that may provide a deeper understanding of resistivity and conduction.
Participants express varying views on the necessity and feasibility of deriving Ohm's law from quantum mechanics, with some advocating for a focus on understanding the underlying principles rather than specific derivations. There is no consensus on whether a definitive quantum mechanical derivation exists.
Participants reference different models of electron conduction, highlighting limitations in the classical approach and the need for quantum explanations, particularly regarding temperature dependence of resistivity. However, specific assumptions and mathematical steps in these models remain unresolved.
johnathon said:I'm watching MIT 8.02 electricity and magnetism () and the lecturer says that there is a derivation of ohm's law but it uses quantum mechanics which is outside the scope of the course. Does anybody know of this derivation and can point me to it? I searched around but can't find anything
physwizard said:the basic model for conduction is the drude model. this assumes that electrons behave like billiard balls. this is enough to prove ohms law. the quantum model is the drude-sommerfield model. here electrons behave like waves and scatter off impurity atoms. then there is a more advanced model call nearly free electron model. anyways the quantum theory successfully explains the temperature dependence of resistivity which the classical drude model is not able to . i would say not to bother with derivations, the important thing is to understand how conduction happens from the quantum mechanical perspective.