Rectified Lorentz Force from Thermal Current Fluctuations

In a conducting medium held at finite temperature, free carriers perform Brownian motion and generate fluctuating electromagnetic fields. In this paper, an averaged Lorentz force density is computed that turns out to be nonzero in a thin subsurface layer, pointing towards the surface, while it vanishes in the bulk. This is an elementary example of rectified fluctuations, similar to the Casimir force or radiative heat transport. The results obtained also provide an experimental way to distinguish between the Drude and so-called plasma models.