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Main Authors: Zhang, Liang, Pan, Chenhao, He, Jinze, Chen, Danni, Zhao, Zirui, Cheng, Qingqing, Pan, Yiming
Format: Preprint
Published: 2025
Subjects:
Online Access:https://arxiv.org/abs/2510.08995
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author Zhang, Liang
Pan, Chenhao
He, Jinze
Chen, Danni
Zhao, Zirui
Cheng, Qingqing
Pan, Yiming
author_facet Zhang, Liang
Pan, Chenhao
He, Jinze
Chen, Danni
Zhao, Zirui
Cheng, Qingqing
Pan, Yiming
contents Photonic time crystals (PTCs) - dielectric media whose permittivity is periodically modulated in time - map to a Dirac equation with an imaginary mass, opening a momentum gap (k-gap) where modes grow or decay exponentially. Here, we introduce a sequence of temporal Jackiw-Rebbi kinks that act as a programmable flip of the Dirac mass, exchanging the amplifying and decaying in-gap modes. By launching two seeded pulses with a controlled relative phase, we demonstrate topological pair annihilation in spacetime domain, the phase-selective cancellation of counter-propagating, k-gap-amplified modes. The resulting spatiotemporal cascade appears superluminal, yet causality is preserved because the cascaded pattern carries no net energy flux. To facilitate implementation, we construct a minimal time-varying non-Hermitian lattice model and reproduce the phase-selective pair annihilation behavior, establishing a direct continuum-lattice correspondence. Our results identify topological kinks as temporal gating to manipulate the growth and wave propagation of time-varying media.
format Preprint
id arxiv_https___arxiv_org_abs_2510_08995
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Topologically-protected superluminal pair annihilation in photonic time crystals
Zhang, Liang
Pan, Chenhao
He, Jinze
Chen, Danni
Zhao, Zirui
Cheng, Qingqing
Pan, Yiming
Optics
Photonic time crystals (PTCs) - dielectric media whose permittivity is periodically modulated in time - map to a Dirac equation with an imaginary mass, opening a momentum gap (k-gap) where modes grow or decay exponentially. Here, we introduce a sequence of temporal Jackiw-Rebbi kinks that act as a programmable flip of the Dirac mass, exchanging the amplifying and decaying in-gap modes. By launching two seeded pulses with a controlled relative phase, we demonstrate topological pair annihilation in spacetime domain, the phase-selective cancellation of counter-propagating, k-gap-amplified modes. The resulting spatiotemporal cascade appears superluminal, yet causality is preserved because the cascaded pattern carries no net energy flux. To facilitate implementation, we construct a minimal time-varying non-Hermitian lattice model and reproduce the phase-selective pair annihilation behavior, establishing a direct continuum-lattice correspondence. Our results identify topological kinks as temporal gating to manipulate the growth and wave propagation of time-varying media.
title Topologically-protected superluminal pair annihilation in photonic time crystals
topic Optics
url https://arxiv.org/abs/2510.08995