Drude model
= Drude model
{c}
The <Drude model> describes classical charge carriers accelerated by an applied electric field and randomized by collisions of constant mean waiting time $\tau$. Its mean drift obeys $\dot v+v/\tau=eE/m$, and harmonic conductivity is $ne^2\tau/[m(1-i\omega\tau)]$ in the negative-frequency exponential convention.