تقرير
Symmetry-induced higher-order exceptional points in two dimensions
| العنوان: | Symmetry-induced higher-order exceptional points in two dimensions |
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| المؤلفون: | Montag, Anton, Kunst, Flore K. |
| المصدر: | Phys. Rev. Research 6, 023205 (2024) |
| سنة النشر: | 2024 |
| المجموعة: | Condensed Matter Physics (Other) Quantum Physics |
| مصطلحات موضوعية: | Condensed Matter - Mesoscale and Nanoscale Physics, Physics - Optics, Quantum Physics |
| الوصف: | Exceptional points of order $n$ (EP$n$s) appear in non-Hermitian systems as points where the eigenvalues and eigenvectors coalesce. They emerge if $2(n-1)$ real constraints are imposed, such that EP2s generically appear in two dimensions (2D). Local symmetries have been shown to reduce this number of constraints. In this work, we provide a complete characterization of the appearance of symmetry-induced higher-order EPs in 2D parameter space. We find that besides EP2s only EP3s, EP4s, and EP5s can be stabilized in 2D. Moreover, these higher-order EPs must always appear in pairs with their dispersion determined by the symmetries. Upon studying the complex spectral structure around these EPs, we find that depending on the symmetry, EP3s are accompanied by EP2 arcs, and two- and three-level open Fermi structures. Similarly, EP4s and closely related EP5s, which arise due to multiple symmetries, are accompanied by exotic EP arcs and open Fermi structures. For each case, we provide an explicit example. We also comment on the topological charge of these EPs, and discuss similarities and differences between symmetry-protected higher-order EPs and EP2s. |
| نوع الوثيقة: | Working Paper |
| DOI: | 10.1103/PhysRevResearch.6.023205 |
| URL الوصول: | http://arxiv.org/abs/2401.10913 |
| رقم الأكسشن: | edsarx.2401.10913 |
| قاعدة البيانات: | arXiv |
| DOI: | 10.1103/PhysRevResearch.6.023205 |
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