Fig. 3: Mode evolution of asymmetric vortex transmission with chiral protection.
From: Chirality-protected extreme asymmetric acoustic information transport with noise immunity
a Simulated energy flow ratio (transmittance) between transmission and incident (1,0) mode during forward (Tf) and backward (Tb) transmission. b Measured transmittance of each mode. c Simulated and measured the transmittance of mode (1,1) when mode (1,0) is incident in the forward and backward directions, The transmission contrast ratio shown in the lower panel is defined as σ = Tf/Tb. Circles: experiment. Solid line: simulation. d Simulated and measured sound field distributions on the transmitted side on the cross section at a distance z = 4λ from the metamaterial. Left and right panels indicate the forward (propagable) and backward (isolated) directions, respectively. Top row: the real part of pressure p. Bottom row: phase of the vortex.
