Universal Route for the Emergence of Exceptional Points in PT-Symmetric Metamaterials with Unfolding Spectral Symmetries

Abstract

We introduce a class of Parity-Time symmetric elastodynamic metamaterials (Ed-MetaMater) whose Hermitian counterpart exhibits a frequency spectrum with unfolding (fractal) symmetries. Our study reveals a scale-free formation of exceptional points (EP) whose density is dictated by the fractal dimension of their Hermitian spectra. Demonstrated in a quasi-periodic Aubry-Harper, a geometric H-tree-fractal, and an aperiodic Fibonacci Ed-MetaMater, the universal route for EP-formation is established via a coupled mode theory model with controllable fractal spectrum. This universality will enable the rational design of novel Ed-MetaMater for hypersensitive sensing and elastic wave control.

References in corpus (2)

• Non-Hermitian Ring Laser Gyroscopes with Enhanced Sagnac Sensitivity
• Linking scalar elastodynamics and non-Hermitian quantum mechanics

Cited by in corpus (4)

• Floquet engineering of point-gapped topological superconductors
• Emergence of Exceptional Points in Periodic Metastructures with Hidden PT-symmetric Defects
• Imaginary spin-orbital coupling in parity-time symmetric systems with momentum-dependent gain and loss
• Damping Reveals Hidden Dimensions in Elastic Metastructures Through Induced Transparency