  In materials with an intrinsic magnetoelectric (ME) effect, the energy
density comprises the polarization, magnetization and ME energy densities.
These three components of energy define local (subwavelength) characteristics
of electromagnetic (EM) responses in multiferroic materials. In a subwavelength
domain, coupling between the electric and magnetic dipole oscillations forms
the ME field structures which are characterized by the violation of both
spatial and temporal symmetry. Unlike multiferroics, bi(an)isotropic
metamaterials are associated with an EM response characterized only by spatial
symmetry breaking. This also applies to chiral materials. Since no intrinsic
magnetoelectricity is assumed in such structures, any concepts about the stored
ME energy are not applicable. This clearly points to the effect of nonlocality.
That is why the basic concepts of bi(an)isotropy can only be analyzed by the EM
far field characteristics. In this paper, we argue that in the implementation
of local (subwavelength) ME meta atoms and systems for near field probing of
chirality, the concept on ME energy is crucial. Real ME energy can occur when
ME fields in a singular subwavelength domain are characterized by a violation
of both the symmetry of time reversal and spatial reflection.
