Non-Hermitian topology and skin modes in the continuum via parametric processes

TL;DR

This paper shows how parametric processes in bosonic systems can induce non-Hermitian topological phases and skin effects, providing a simpler alternative to complex bath engineering with potential for scalable applications.

Contribution

It introduces a model where local dissipation and parametric drives create non-Hermitian topology and skin modes, establishing a bulk-boundary correspondence in continuum systems.

Findings

Observation of non-Hermitian skin effect with localized edge modes

Identification of exceptional points and tilted diabolical lines in dispersion

Robust bulk-boundary correspondence via bulk winding indices

Abstract

We demonstrate that Hermitian, nonlocal parametric pairing processes can induce non-Hermitian topology and skin modes, offering a simple alternative to complex bath engineering. Our model, stabilized by local dissipation and operating in the continuum limit, reveals exceptional points that spawn a tilted diabolical line in the dispersion. Local dissipation prevents instabilities, while a bulk anomaly signals unscreened current response. Upon opening the boundaries, we observe a non-Hermitian skin effect with localized edge modes. Through bulk winding indices and non-Bloch theory, we establish a robust bulk-boundary correspondence, highlighting parametric drives as a scalable route to non-Hermitian topology in bosonic systems.