Topological split-ring resonator based metamaterials with $\cal PT$ symmetry relying on gain and loss
| Autor: | Giorgos P. Tsironis, Nikos Lazarides |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
Physics
Condensed Matter - Mesoscale and Nanoscale Physics Quadratic eigenvalue problem FOS: Physical sciences Metamaterial Physics::Optics Applied Physics (physics.app-ph) 02 engineering and technology Physics - Applied Physics Parameter space 021001 nanoscience & nanotechnology Topology 01 natural sciences Inductive coupling Symmetry (physics) Split-ring resonator Normal mode Mesoscale and Nanoscale Physics (cond-mat.mes-hall) 0103 physical sciences 010306 general physics 0210 nano-technology Eigenvalues and eigenvectors |
| Popis: | A one-dimensional metamaterial with parity-time (${\cal PT}$) symmetry that relies on balanced gain and loss is introduced, comprising of magnetically coupled split-ring resonators (SRRs). A particular topology that combines a non-trivial (topological) dimer configuration with a trivial (non-topological) dimer configuration which are separated by a central SRR with neither gain or loss, is investigated. By focusing on the dynamical aspects of such a topological ${\cal PT}$ metamaterial (PTMM), the existence of {\em topologically protected interface states} which are localized at the central SRR is demonstrated numerically. The solution of the corresponding {\em quadratic eigenvalue problem} reveals that the protected state is actually a robust eigenmode of the topological PTMM, whose eigenvalue is isolated in the middle of the gap (mid-gap state) of the two-band frequency spectrum. Direct numerical simulations have been further used to determine the robustness and dynamic stability of these states in the parameter space of the {\em dimerization strength} and the {\em gain-loss coefficient}. 8 pages, 7 figures, 45 references. Accepted by Physical Review B as Regular Article |
| Databáze: | OpenAIRE |
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