Abstract

The range of values observed for the magnetic permeability, µ(ω), appears to be more restricted than the values observed for the electric permittivity, ε(ω), where very large, and even negative values are observed. This is in part due to the simple fact that there are no magnetic monopoles to provide the analogous response to that of electrons. In particular, as one moves away from zero frequency, the magnitude of the magnetic response from most materials, or µ(ω), decreases rapidly, and has never been observed to take negative values. While the general lack of magnetic response is observed to be the case, Maxwell’s Equations do not preclude a material having a large µ(ω), either positive or negative. The essential requirement on the material constants appears only to be d /d and d /d for frequency-dependent materials.¹

© 2000 IEEE