Quantum diffusion in the Harper model under polychromatic time-perturbation

Hiroaki S. Yamada; Kensuke S. Ikeda

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arXiv · 2507.18859

Quantum diffusion in the Harper model under polychromatic time-perturbation

Hiroaki S. Yamada·Kensuke S. Ikeda

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Abstract

Quantum dynamics of the Harper model with self-duality exhibits localized, diffusive, and ballistic states depending on the potential strength $V$. By adding time-dependent harmonic perturbations composed of $M$ incommensurate frequencies, we show that all states of the Harper model transition to quantum diffusive states as the perturbation strength $\epsilon$ increases for $M \geq 3$. The transition schemes and diffusion behaviors are discussed in detail and the phase diagram in the $(\epsilon,V)$ parameter space is presented.

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Hiroaki S. Yamada, Kensuke S. Ikeda. 2025-07-25. Quantum diffusion in the Harper model under polychromatic time-perturbation. https://arxiv.org/abs/2507.18859

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