Drift and diffusion

In the model of diffusive transport, electrons repeatedly scatter with a scattering time $\tau$. At a scattering event, the electrons return to their equilibrium velocity and move in a random direction. Between scattering events the electrons move under the influence of the applied electric and magnetic fields. In the simulation below, the blue dots represent electrons. The red dot is the average initial position of the electrons and the green dot is the average position.

The motion of charge particles in constant electric and magnetic fields