Requisites on material viscoelasticity for exceptional points in passive dynamical systems

Abstract Recent progress in non-Hermitian physics and the notion of exceptional point (EP) degeneracies elastodynamics have led to development novel metamaterials for control elastic wave propagation, hypersensitive sensors, actuators. The emergence EPs a parity-time symmetric system relies on judiciously engineered balanced gain loss mechanisms. Creating requires complex circuits amplification mechanisms, making engineering applications challenging. Here, we report strategies achieve passive elastodynamic systems with differential derived from viscoelastic materials. We compare different material models show that EP emerges only when frequency-dependent loss-tangent remains nearly constant frequency range operation. This type tangent occurs materials undergo stress-relaxation over broad spectrum relaxation times, example, follow Kelvin–Voigt fractional derivative (KVFD) model. Using dynamic mechanical analysis, few common elastomers, such as polydimethylsiloxane polyurethane rubber, KVFD behavior becomes almost after particular frequency. present demonstration potential widely available creating pave way developing hypersensitivity perturbations or enhanced emissivity.