Cake meeting talk on thermopower

This week I talk about Kelvin formula for the thermopower. Here are the slides. Not sure that they will be much use for people not at the meeting. At least, they give a flavour of some of the experimental results of particular interest to me. Most have been featured in earlier blog posts on the subject.

I made one small discovery in my preparation: a specific example where the Kelvin formula is exact. If one takes the temperature dependence of the chemical potential for non-interacting fermions with a general density of states [equation 2.77 in Ashcroft and Mermin] then the thermopower from the Kelvin formula is exactly that given by the Mott-Heikes formula obtained from solving the Boltzmann equation [equation 13.62 in Ashcroft and Mermin] for the case where the scattering time and velocity have no energy dependence.