Sensor sensitivity based on synthetic magnetism exceptional point

Abstract: An efficient mass sensor based on exceptional points (EPs), engineered under synthetic magnetism requirement, is proposed. The benchmark system consists of an electromechanical (optomechanical) system where an electric (optical) field is driving two mechanical resonators which are mechanically coupled through a phase-dependent phonon-hopping. This phase induces series of EPs once it matches the condition of $\frac{\pi}{2}(2n +1)$. For any perturbation of the system, the phase-matched condition is no longer satisfied and this lifts the EP-degeneracies leading to a frequency splitting that scales as the square root of the perturbation strength, resulting in a giant sensitivity-factor enhancement. Owing to the set of EPs, our proposal allows multiple sensing scheme and performs better than its anti-PT-symmetric sensor counterpart. This work sheds light on new platforms that can be used for mass sensing purposes, opening up new opportunities in nanoparticles or pollutants detection, and to water treatment.