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arXiv · 1511.08719

Manifestation of anomalous Floquet states with longevity in dynamic fractional Stark ladder with high AC electric fields

Yuya Nemoto·Fumitaka Ohno·Nobuya Maeshima·Ken-ichi Hino
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Abstract

We examine a resonance structure of Floquet state in dynamic fractional Stark ladder (DFSL) realized in biased semiconductor superlattices driven by a terahertz cw laser on the basis of the R-matrix Floquet theory. To do this, we calculate an excess density of state $ρ^{(ex)}(E)$ corresponding to lifetime of the Floquet state with a fractional matching ratio $η$, where $η$ is the ratio of a Bloch frequency $Ω_B$ to a laser frequency $ω$, namely, $η=Ω_B/ω$. The results for $η=3/2$ demonstrate the appearance of discernibly large peaks associated with Floquet states with longevity in a region of relatively high laser-intensity. The underlying physics is discussed in terms of an analytical expression of $ρ^{(ex)}(E)$ and the associated Green function in which ponderomotive couplings are included in a non-perturbative way.

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Yuya Nemoto, Fumitaka Ohno, Nobuya Maeshima, Ken-ichi Hino. 2015-11-27. Manifestation of anomalous Floquet states with longevity in dynamic fractional Stark ladder with high AC electric fields. https://doi.org/10.1016/j.physe.2016.04.021

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