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DOE OSTI · 2316110

Nonlinear wavepacket dynamics in proximity to a stationary inflection point

Landers, Serena·Kurnosov, Arkady·Tuxbury, William·Vitebskiy, Ilya·Kottos, Tsampikos
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Abstract

A stationary inflection point (SIP) in the Bloch dispersion relation of a periodic waveguide is an exceptional point degeneracy where three Bloch eigenmodes coalesce, forming the so-called frozen mode with a divergent amplitude and vanishing group velocity of its propagating component. For this work, we have developed a theoretical framework to study the time evolution of wavepackets centered at an SIP. Analysis of the evolution of the statistical moment distribution of linear pulses shows a strong deviation from the conventional ballistic wavepacket dynamics in dispersive media. The presence of nonlinear interactions dramatically changes the situation, resulting in a mostly ballistic propagation of nonlinear wavepackets with the speed and even the direction of propagation essentially dependent on the wavepacket amplitude. Such a behavior is unique to nonlinear wavepackets centered at an SIP and can be used for the realization of a novel family of beam power routers for classical waves.

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75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITYBloch wave theoryphotonic crystalsphotonicspopulation dynamicstransport phenomena

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Landers, Serena, Kurnosov, Arkady, Tuxbury, William, Vitebskiy, Ilya, Kottos, Tsampikos. 2024-01-25. Nonlinear wavepacket dynamics in proximity to a stationary inflection point. https://doi.org/10.1103/physrevb.109.024312

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