Superluminal Signals

摘要

Photonic tunneling realizes superluminal signal velocities predicted indirectly 30 years ago. The basics of superluminal signals preserving causality are sketched from the views of both information theory and physics. The role of forerunners, the problems associated with points of nonanalyticity in a signal and the crucial role of frequency-band and time limitation of signals are addressed. Applications of the results range from optical networking over metamaterials also realizing superluminal causal signal velocities to the radiative exchange of heat between nanostructures via photonic tunneling.