# Unambiguous scattering matrix for non-Hermitian systems

@article{Novitsky2020UnambiguousSM,
title={Unambiguous scattering matrix for non-Hermitian systems},
author={Andrey Novitsky and Dmitry A. Lyakhov and Dominik Ludewig Michels and Alexander A. Pavlov and Alexander S. Shalin and Denis V. Novitsky},
journal={Physical Review A},
year={2020}
}
• Published 2 April 2020
• Physics
• Physical Review A
$\mathcal{PT}$ symmetry is a unique platform for light manipulation and versatile use in unidirectional invisibility, lasing, sensing, etc. Broken and unbroken $\mathcal{PT}$-symmetric states in non-Hermitian open systems are described by scattering matrices. A multilayer structure, as a simplest example of the open system, has no certain definition of the scattering matrix, since the output ports can be permuted. The uncertainty in definition of the exceptional points bordering $\mathcal{PT… 9 Citations ## Figures from this paper Parity-Time Symmetry and Exceptional points: A Tutorial • Physics • 2021 The physics of systems that cannot be described by a Hermitian Hamiltonian, has been attracting a great deal of attention in recent years, motivated by their nontrivial responses and by a plethora of Symmetry-Protected Scattering in Non-Hermitian Linear Systems • Physics Chinese Physics Letters • 2021 Symmetry plays fundamental role in physics and the nature of symmetry changes in non-Hermitian physics. Here the symmetry-protected scattering in non-Hermitian linear systems is investigated by CPA-lasing associated with the quasibound states in the continuum in asymmetric non-Hermitian structures • Physics • 2022 Non-Hermitian photonic systems with loss and gain attract much attention due to their exceptional abilities in molding the ﬂow of light. Introducing asymmetry to the PT -symmetric system with Nonlinear scattering by non-Hermitian multilayers with saturation effects. • Physics Physical review. E • 2021 It is shown that by tuning the parameters of the layers the authors can effectively control the impact of nonlinearity on the scattering characteristics of the non-Hermitian layered structure. Unitary Scattering Protected by Pseudo-Hermiticity • L. Jin • Physics, Mathematics Chinese Physics Letters • 2022 Hermitian systems possess unitary scattering. However, the Hermiticity is unnecessary for a unitary scattering although the scattering under the influence of non-Hermiticity is mostly non-unitary. Multimode -symmetry thresholds and third-order exceptional points in coupled dielectric waveguides with loss and gain • Physics Journal of Optics • 2021 A pair of coupled dielectric waveguides with balanced loss and gain is the basic system for observing the phenomena of parity-time ( ) symmetry and exceptional points (EPs). We use the multimode Quasibound states in the continuum induced by PT symmetry breaking • Physics Physical Review B • 2021 Denis V. Novitsky1,∗ Alexander S. Shalin2,3,4, Dmitrii Redka5,4, Vjaceslavs Bobrovs, and Andrey V. Novitsky6,2 B. I. Stepanov Institute of Physics, National Academy of Sciences of Belarus, Purcell Effect in PT-Symmetric Waveguides • Physics Topics in Applied Physics • 2021 This chapter overviews the principles of the spontaneous emission rate increase, that is the Purcell effect, in relation to the photonic parity-time (PT) symmetry. Being focused on the system of 1 2 M ar 2 02 1 Quasi-bound states in the continuum induced by PT-symmetry breaking • Physics • 2021 Denis V. Novitsky1,∗ Alexander S. Shalin2,3,4, Alexander A. Pavlov, Vjaceslavs Bobrovs, and Andrey V. Novitsky B. I. Stepanov Institute of Physics, National Academy of Sciences of Belarus, ## References SHOWING 1-10 OF 43 REFERENCES Demonstration of a two-dimensional $${\cal P}{\cal T}$$PT-symmetric crystal • Physics Nature communications • 2019 The authors experimentally realize and characterize a two-dimensional PT-symmetric system using photonic lattice waveguides with judiciously designed refractive index landscape and an alternating loss distribution. CPA-laser effect and exceptional points in${\mathscr{PT}}\$-symmetric multilayer structures
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