Emergence of Exceptional Points in Periodic Metastructures with Hidden PT-symmetric Defects
Dear Colleagues, Our recent publication on the Journal of Applied Mechanics:
Parity-Time symmetry
Exceptional-point-based accelerometers with enhanced signal-to-noise ratio
Exceptional points (EP) are non-Hermitian degeneracies where eigenvalues and their corresponding eigenvectors coalesce. Recently, EPs have attracted attention as a means to enhance the responsivity of sensors, through the abrupt resonant detuning occurring in their proximity. In many cases, however, the EP implementation is accompanied by noise enhancement, leading to the degradation of the sensor’s performance.
Universal route for the emergence of exceptional points in PT-symmetric metamaterials with unfolding spectral symmetries
We introduce a class of parity-time symmetric elastodynamic metamaterials (Ed-MetaMater) whose Hermitian counterpart exhibits unfolding (fractal) spectral symmetries. Our study reveals a scale-free formation of exceptional points in those Ed-MetaMaters whose density is dictated by the fractal dimension of their Hermitian spectra.
Environmentally induced exceptional points in elastodynamics
We study the nature of an environment-induced exceptional point in a non-Hermitian pair of coupled mechanical oscillators. The mechanical oscillators are a pair of pillars carved out of a single isotropic elastodynamic medium made of aluminum and consist of carefully controlled differential losses. The interoscillator coupling originates exclusively from background modes associated with the “environment,” that portion of the structure which, if perfectly rigid, would support the oscillators without coupling.