TY  - JOUR
A1  - Kremer, Mark
A1  - Biesenthal, Tobias
A1  - Maczewsky, Lukas J.
A1  - Heinrich, Matthias
A1  - Thomale, Ronny
A1  - Szameit, Alexander
T1  - Demonstration of a two-dimensional PT-symmetric crystal
T2  - Nature Communications
N2  - With the discovery of PT-symmetric quantum mechanics, it was shown that even non-Hermitian systems may exhibit entirely real eigenvalue spectra. This finding did not only change the perception of quantum mechanics itself, it also significantly influenced the field of photonics. By appropriately designing one-dimensional distributions of gain and loss, it was possible to experimentally verify some of the hallmark features of PT-symmetry using electromagnetic waves. Nevertheless, an experimental platform to study the impact of PT-symmetry in two spatial dimensions has so far remained elusive. We break new grounds by devising a two-dimensional PT-symmetric system based on photonic waveguide lattices with judiciously designed refractive index landscape and alternating loss. With this system at hand, we demonstrate a non-Hermitian two-dimensional topological phase transition that is closely linked to the emergence of topological mid-gap edge states.
KW  - micro-optics
KW  - optical materials and structures
KW  - topological matter
Y1  - 2019
UR  - https://opus.bibliothek.uni-wuerzburg.de/opus4-wuerzburg/frontdoor/index/index/docId/23013
UR  - https://nbn-resolving.org/urn:nbn:de:bvb:20-opus-230132
VL  - 10
ER  -