# Demonstration of a two-dimensional $${\cal P}{\cal T}$$PT-symmetric crystal

@article{Kremer2019DemonstrationOA, title={Demonstration of a two-dimensional \$\$\{\cal P\}\{\cal T\}\$\$PT-symmetric crystal}, author={Mark Kremer and Tobias Biesenthal and Lukas J. Maczewsky and Matthias Heinrich and Ronny Thomale and Alexander Szameit}, journal={Nature Communications}, year={2019}, volume={10}, pages={1-7} }

With the discovery of $${\cal P}{\cal T}$$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 $${\cal P}{\cal T}$$PT-symmetry using…

## 43 Citations

Symmetry-engineered waveguide dispersion in $ {\cal P}{\cal T} $PT symmetric photonic crystal waveguides

- Physics
- 2019

This work demonstrates how the crystal symmetry of photonic crystal defect waveguides interacts with simple, experimentally realizable parity-time ($ {\cal P}{\cal T} $PT) symmetric regions of…

Unambiguous scattering matrix for non-Hermitian systems

- PhysicsPhysical Review A
- 2020

$\mathcal{PT}$ 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…

Topological protection in non-Hermitian Haldane honeycomb lattices

- Physics
- 2020

Topological phenomena in non-Hermitian systems have recently become a subject of great interest in the photonics and condensed-matter communities. In particular, the possibility of observing…

Nonlinear tuning of PT symmetry and non-Hermitian topological states

- PhysicsScience
- 2021

It is found that the loss in a topological defect potential in a non-Hermitian photonic lattice can be tuned solely by nonlinearity, enabling the transition between PT-symmetric and non–PT-Symmetric regimes and the maneuvering of topological zero modes.

2D Solitons in PT-Symmetric Photonic Lattices.

- PhysicsPhysical review letters
- 2019

This work presents an experimental platform for investigating the interplay between PT symmetry and nonlinearity in two-dimensional environments, where nonlinear localization and soliton formation can be observed and demonstrates a one-parameter family of soliton solutions that are capable of displaying attributes similar to those encountered in nonlinear conservative arrangements.

Nonlinear control of PT-symmetry and non-Hermitian topological states

- Physics
- 2020

Advances in topological photonics and non-Hermitian optics have drastically changed our perception on how interdisciplinary concepts may empower unprecedented applications. Bridging the two areas…

Topological funneling of light

- PhysicsScience
- 2020

Using a time-dependent photonic lattice in which the topological properties can be controlled, Weidemann et al. show that such a structure can efficiently funnel light to the interface irrespective of the point of incidence on the lattice.

Experimental Realization of PT-Symmetric Flat Bands.

- PhysicsPhysical review letters
- 2019

This work experimentally demonstrates that, far from being a nuisance to be compensated, judiciously tailored loss distributions can, in fact, be the key ingredient in synthesizing such flat bands in non-Hermitian environments.

Realization of photonic charge-2 Dirac point by engineering super-modes in topological superlattices

- Physics
- 2019

Quite recently, an unconventional variety of fourfold linear band degeneracy points has been discovered in certain condensed-matter systems. Contrary to standard 3-D Dirac monopoles, these quadruple…

Topological Defect Engineering and PT Symmetry in Non-Hermitian Electrical Circuits.

- PhysicsPhysical review letters
- 2021

The findings unveil a future route for topological defect engineering and tuning in non-Hermitian systems of arbitrary dimension and resolve not only topological edge states, but also a novel PT-symmetric Z_{2} invariant of the bulk.

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