Zener tunneling of acoustic waves in a one-dimensional phononic crystal

We numerically study the Zener tunneling of acoustic waves in a one-dimensional phononic crystal (PC). The PC is designed to possess two minibands separated by a narrow frequency gap, which further form two acoustic Wannier–Stark ladders when an increasing gradient in the width of elementary cell of PC is introduced. Resonant tunneling between two Wannier–Stark states in different minibands is observed.