Instability of Dynamic Localization in the Intense THz-Driven Semiconductor Wannier-Stark Ladder due to the dynamic Fano resonance

Instability of an electronic Floquet state in the semiconductor Wannier‐Stark ladder (WSL) driven by an intense monochromatic THz wave is investigated by virtue of the R‐matrix Floquet theory. It is revealed that a dynamic localization (DL) characteristic of this system is unstable against the Fano resonance‐like interminiband decay mechanism caused by the THz‐mediated interaction, termed here the dynamic Fano resonance (DFR). The result obtained here is sharply contrasted with the conventional understanding without the introduction of DFR that the degree of stability of the DL would be comparable to that of the WSL with no THz drive.