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

Abstract

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 could uncover the reciprocity between topology and non-Hermiticity in complex systems. So far, such endeavors have focused mainly on linear-optics regime. Here, we establish a nonlinear non-Hermitian topological platform for control of parity-time (PT) symmetry and topological edge states. Experimentally, we demonstrate that optical nonlinearity effectively modulates the gain and loss of a topological interface waveguide in a non-Hermitian Su-Schrieffer-Heeger lattice, leading to switching between PT and non-PT-symmetric regimes accompanied by destruction and restoration of topological zero modes. Theoretically, we examine the fundamental issue of the interplay between two antagonistic effects: the sensitivity close to exceptional points and the robustness of non-Hermitian topological modes. Realizing single-channel control of global PT-symmetry via local nonlinearity may herald new possibilities for light manipulation and unconventional device applications.

References in corpus (2)

• Efficient Light Funneling based on the non-Hermitian Skin Effect
• Selective enhancement of topologically induced interface states in a dielectric resonator chain

Cited by in corpus (9)

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• Linear response theory of open systems with exceptional points
• Dark topological valley Hall edge solitons
• Transforming space with non-Hermitian dielectrics
• Exceptional points in oligomer chains
• A thermodynamic description of the near- and far-field intensity patterns emerging from multimode nonlinear waveguide arrays
• Quantum transport in nonlinear Rudner-Levitov models