Arbitrarily Configurable Nonlinear Topological Modes.

Area of Science:

• Condensed Matter Physics
• Nonlinear Optics
• Topological Materials

Background:

• Topological modes (TMs) are usually confined to boundaries and decay into the bulk.
• The non-Hermitian skin effect has shown promise in delocalizing TMs, increasing their capacity.
• Controlling TM wave functions is crucial for developing advanced topological devices.

Purpose of the Study:

• To investigate the potential of nonlinearity in designing and configuring topological mode wave functions.
• To explore the behavior of nonlinear topological modes (NTMs) with increasing intensity.
• To assess the robustness and stability of these engineered NTMs.

Main Methods:

• Theoretical exploration of nonlinearity's effect on topological mode wave functions.
• Analysis of wave function behavior under varying intensity, including deviation from exponential decay, plateau formation, domain extension, and boundary concentration.
• Investigation of robustness against defects and disorders, and dynamic stability under external excitation.

Main Results:

• Nonlinearity allows for the designable extension of topological mode wave functions.
• Wave functions transition from exponential decay to plateaus and eventually concentrate at nonlinear boundaries.
• Extended nonlinear topological modes exhibit robustness against defects and disorders.
• These modes demonstrate stable dynamics under external excitation.

Conclusions:

• Nonlinearity offers a powerful tool for engineering topological mode wave functions.
• Extended nonlinear topological modes can significantly increase capacity and offer robust performance.
• This work opens new pathways for developing compact, configurable, and high-capacity topological devices.