Fig. 2: In-plane phase evolutions and wave transport behaviors of the elastic near-zero refractive index metamaterial (NZIM).
From: Topologically protected zero refraction of elastic waves in pseudospin-Hall phononic crystals
a–c The simulated phase distributions of the Uy displacement field for a transverse wave incidence from the left along the x direction (ΓM), at f = 89.830, 89.692, and 89.560 kHz, respectively. d Phase of the displacement field at the marked points by white dots in figures of a–c. e Total displacement field distributions of near-zero index phononic crystals (PCs) surrounded by aluminum. f Same as e, except that the simulated triangular region is replaced by a homogeneous zero refractive index medium. g In-plane displacement (acoustic pressure) field of near-zero index PCs surrounded by water. A point source is placed at the center of a triangular region (marked by black dot), at the Dirac frequency fD = 89.692 kHz. Black arrows denote the propagation direction of the waves.
