A nonlinear exceptional nexus with an ultra-enhanced signal-to-noise ratio

Prof. Duanduan Wan and Prof. Meng Xiao at the School of Physics of Wuhan University recently published a study in the journal National Science Review. Their work provides a simple while intuitive example, demonstrating with both theory and circuit experiments an “exceptional nexus” (“EX”), a higher-order exceptional point (HOEP). This HOEP is realized within only two coupled resonators with the aid of nonlinear gain. Moreover, such a HOEP exhibits an ultra-enhanced signal-to-noise ratio.