The origin of non-Drude terahertz conductivity in nanomaterials

Abstract

The Drude-Smith (DS) model hitherto has been a well accepted model for the terahertz conductivity of nanomaterials, even though its physical basis is not clear. It is shown that a series sequence of transport involving grains and grain boundaries produces a Lorentzian-type energy loss and dominates the THz conductivity in nanomaterials, which is able to explain both the real and imaginary parts of the conductivity. The present model represents a completely different point of view than the standard Drude-Smith model.