The beat time { \tau}_{ fpt} associated with the energy transfer between two coupled oscillators is dictated by the bandwidth theorem which sets a lower bound { \tau}_{ fpt}\sim 1/{ \delta}{ \omega}. We show, both experimentally and theoretically, that two coupled active LRC electrical oscillators with parity-time (PT) symmetry, bypass the lower bound imposed by the bandwidth theorem, reducing the beat time to zero while retaining a real valued spectrum and fixed eigenfrequency difference { \delta}{ \omega}. Our results foster new design strategies which lead to (stable) pseudo-unitary wave evolution, and may allow for ultrafast computation, telecommunication, and signal processing.
Categories: physics.class-ph cond-mat.other quant-ph