Autler-Townes Splitting and Acoustically Induced Transparency Based on Love Waves Interacting with a Pillared Metasurface

Autler-Townes splitting (ATS) and electromagnetically induced transparency (EIT) are similar phenomena but distinct in nature. They have been widely discussed and distinguished by employing the Akaike information criterion (AIC). However, such work is lacking in acoustic systems. In this work, the interaction of Love waves with a two-line pillared metasurface is numerically investigated by the finite-element method. An acoustic analog of ATS, Fabry-Perot resonance, and cavity modes are first demonstrated in two lines of identical pillars by varying the distance between the pillar lines. By detuning the radius of one line of pillars, Fabry-Perot resonance along with two different pillar resonances give rise to the acoustic analog of EIT (AIT) when the distance between the pillar lines is a multiple of half wavelength. ATS and AIT formula models are used to fit the transmission spectra, showing good agreements with numerical results. The quality of the fit models is quantitatively evaluated by resorting to the AIC. We show that theoretical and analytical discrimination between ATS and AIT are methodologically complementary. These results should have consequences for potential acoustic applications such as wave control, and the design of metamaterials and biosensors.