On Lorentz and Einstein-Laub forces in material media

Abstract

As a continuation of the discussion started in (M. Mansuripur, Phys. Rev. Lett. 108, 193901 (2012)), we show that the approach based on Lorentz force law in material media, like Einstein-Laub expression for electromagnetic force, gives relativistically consistent results, when the contribution of hidden momentum is properly accounted for. An expression for the torque on point-like electric/magnetic dipole is derived, which is compatible with both the Lorentz and Einstein-Laub approaches.