https://doi.org/10.1140/epjb/s10051-025-01066-2
Regular Article - Statistical and Nonlinear Physics
Emergence of caustics in dynamics of the Kitaev model
Department of Physics, University of Calcutta, 92 A. P. C. Road, 700009, Kolkata, India
Received:
9
February
2025
Accepted:
6
October
2025
Published online:
24
October
2025
We study quasiparticle dynamics in two-dimensional (2D) integrable Kitaev honeycomb model, both without and in the presence of an external periodic drive. We identify light cones in wavefunction propagation as a signature of quantum caustics, i.e., bright structures formed during quantum dynamics analogous to that of imperfect focusing in geometrical optics. We show that this dynamics follows an angle in spatial direction and it is anisotropic with respect to model parameters. Using coalescence of critical points, we provide an exact solution to the envelope of caustics, which corresponds to the Lieb–Robinson bound in 2D. Further, considering the system to be periodically driven, we point out that the caustics structure completely changes in the presence of external time-dependent drive.
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© The Author(s), under exclusive licence to EDP Sciences, SIF and Springer-Verlag GmbH Germany, part of Springer Nature 2025
Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
