Bypassing the bandwidth theorem with PT symmetry

Hamidreza Ramezani, J. Schindler, F. M. Ellis, Uwe Guenther, Tsampikos Kottos

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.

http://arxiv.org/abs/1205.1847
Classical Physics (physics.class-ph)