Gouy Phase across PT-Symmetry Breaking in Non-Hermitian Dirac Systems
Abstract
We study relativistic beam-like wave packets governed by a quasi-Hermitian massive Dirac Hamiltonian and uncover anomalous Gouy-phase behavior in non-Hermitian dynamics. We show that the Gouy phase provides a sensitive probe of the global π«π―-symmetry-breaking threshold: it remains purely real in the globally unbroken, quasi-Hermitian regime, while, after crossing the exceptional point, the Gouy phase changes sign and acquires an imaginary component. At the exceptional point, the Gouy-phase variation vanishes in the small-mass limit but becomes maximal for large masses, revealing a counterintuitive crossover from effectively classical to increasingly wave-like quantum behavior. We propose an experimental scheme to measure the components of the non-Hermitian Gouy phase in the broken regime by monitoring the attenuation of a light beam propagating through a lossy waveguide. These results highlight the potential of the non-Hermitian Gouy phase for photonic applications, including the determination of threshold conditions and the design and control of systems with gain and loss.
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BibTeX
@misc{sousa2026gouy,
title = {{Gouy Phase across PT-Symmetry Breaking in Non-Hermitian Dirac Systems}},
author = {Dirlan J. C. de Morais Sousa and Lucas S. Marinho and Giandomenico Palumbo and Irismar G. da Paz},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.01884},
eprint = {2609.01884},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.01884},
}
RIS
TY - UNPB
TI - Gouy Phase across PT-Symmetry Breaking in Non-Hermitian Dirac Systems
AU - Dirlan J. C. de Morais Sousa
AU - Lucas S. Marinho
AU - Giandomenico Palumbo
AU - Irismar G. da Paz
PY - 2026
DA - 2026/09/01
PB - arXiv
DO - 10.48550/arxiv.2609.01884
UR - https://arxiv.org/abs/2609.01884
AB - We study relativistic beam-like wave packets governed by a quasi-Hermitian massive Dirac Hamiltonian and uncover anomalous Gouy-phase behavior in non-Hermitian dynamics. We show that the Gouy phase provides a sensitive probe of the global π«π―-symmetry-breaking threshold: it remains purely real in the globally unbroken, quasi-Hermitian regime, while, after crossing the exceptional point, the Gouy phase changes sign and acquires an imaginary component. At the exceptional point, the Gouy-phase variation vanishes in the small-mass limit but becomes maximal for large masses, revealing a counterintuitive crossover from effectively classical to increasingly wave-like quantum behavior. We propose an experimental scheme to measure the components of the non-Hermitian Gouy phase in the broken regime by monitoring the attenuation of a light beam propagating through a lossy waveguide. These results highlight the potential of the non-Hermitian Gouy phase for photonic applications, including the determination of threshold conditions and the design and control of systems with gain and loss.
ER -