Charge carrier mobility
= Charge carrier mobility
{title2=$\mu=|q|\tau/m$}
<Charge carrier mobility> is the magnitude of steady <drift velocity> per unit weak <electric field> in a scalar transport model. In the <Drude model>, $\mathbf v_d=\operatorname{sgn}(q)\mu\mathbf E$ and $\sigma=n|q|\mu$. The positive <charge carrier mobility> separates ease of motion from the sign of <electric charge>; its <SI> unit is $\mathrm{m^2/(V\,s)}$.