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arXiv · 2401.13286

Dynamics of non-Hermitian Floquet Wannier-Stark system

H. P. Zhang·K. L. Zhang·Z. Song
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Abstract

We study the dynamics of the non-Hermitian Floquet Wannier-Stark system in the framework of the tight-binding approximation, where the hopping strength is a periodic function of time with Floquet frequency $\omega$. It is shown that the energy level of the instantaneous Hamiltonian is still equally spaced and independent of time $t$ and the Hermiticity of the hopping term. In the case of off resonance, the dynamics are still periodic, while the occupied energy levels spread out at the resonance, exhibiting $t^z$ behavior. Analytic analysis and numerical simulation show that the level-spreading dynamics for real and complex hopping strengths exhibit distinct behaviors and are well described by the dynamical exponents $z=1$ and $z=1/2$, respectively.

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H. P. Zhang, K. L. Zhang, Z. Song. 2024-01-24. Dynamics of non-Hermitian Floquet Wannier-Stark system. https://doi.org/10.1088/1367-2630/ad9d70

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