Floquet-Bloch Oscillations and Intraband Zener Tunneling in an Oblique Spacetime Crystal

摘要

We study an oblique spacetime crystal realized by a monoatomic crystal in which a sound wave propagates, and analyze its quasienergy band structure starting from a tight-binding Bloch band for the static crystal. We investigate Floquet-Bloch oscillations under an external field, which show different characteristics for different band topologies. We also discover intraband Zener tunneling beyond the adiabatic limit, which effectively converts between different band topologies. Our results indicate the possibility of energy conversion between the sound wave and a dc electric field.