Exceptional points of degeneracy in linear time periodic systems and exceptional sensitivity

Abstract

Disclosed herein is an exceptional points of degeneracy (EPD) system with a resonator by introducing a linear time-periodic variation. In contrast, prior art systems with EPD require two coupled resonators with precise values of gain and loss and a precise symmetry of inductances and capacitances. The disclosed EPD system only requires the tuning of the modulation frequency or modulation depth, which can be easily achieved in electronic systems. The EPD is a point in a system parameters' space at which two or more eigenstates coalesce, and this leads to unique properties not occurring at other non-degenerate operating points. Also disclosed are experimental data showing the existence of a second order EPD in a time-varying single resonator and the expected sensitivity of its resonances to circuit perturbations. The disclosed EPD system exhibits structural degenerate and non-degenerate resonances whose dynamics dramatically boosts its sensitivity performance to very small perturbations. The unique sensitivity induced by an EPD can be employed to create exceptionally-sensitive sensors based on a resonator by simply applying time modulation.