A single susceptibility scheme of macroscopic Maxwell equations: beyond the 'E, D, B, H' approach

A new single susceptibility scheme of macroscopic Maxwell equations has been derived by applying a long wavelength approximation to the general form of microscopic response represented by the simultaneous integral equations of induced current density and vector potential. The result turns out to be more general than the conventional 'E,D,B,H' scheme. The new (single) susceptibility contains the contributions of electric and magnetic polarizations together with their mutual interference effect in its different order terms of wavevector k. The conventional description via ε and μ can be reproduced only in the absence of chiral symmetry, under the additional condition that magnetic susceptibility defined with respect, not to H, but to B should be used. In the presence of chiral symmetry, the phenomenological Drude-Born-Fedorov constitutive equations cannot be justified by this microscopic approach