How to achieve exceptional points in coupled resonators using a gyrator or PT-symmetry, and in a time-modulated single resonator: high sensitivity to perturbationsAlireza Nikzamir, Kasra Rouhi, Alexander Figotin and Filippo CapolinoEPJ Appl. Metamat., 9 (2022) 14DOI: https://doi.org/10.1051/epjam/2022006
