A New Look on the Skin Depth of the Normal Skin Effect in a Metal Submitted to a Frequency-Dependent Electromagnetic Field

The theory of the skin depth in metals is re-examined by revision of the conductivity expression entering the Maxwell equations leading to the normal skin effect. In fact this conductivity formula should be improved by considering its special behaviour at low temperatures in case of the presence of the magnetic field. For very pure specimens and very low temperatures the correction of the conductivity tensor leads to the skin depth approximately proportional to the square root of the amplitude strength of the magnetic field.