Topological dynamics in an optomechanical system with highly non-degenerate modes

TL;DR

This paper demonstrates a novel optomechanical scheme that creates a virtual exceptional point between highly non-degenerate modes, enabling topological energy transfer in non-Hermitian systems beyond near-degenerate regimes.

Contribution

It introduces a method to achieve topological control between highly non-degenerate modes using a virtual exceptional point in a non-Hermitian system.

Findings

Achieved a virtual exceptional point between modes with >10^3 frequency difference.

Enabled adiabatic topological energy transfer between non-degenerate modes.

Scheme is broadly applicable to various physical systems.

Abstract

Non-Hermitian systems exhibit phenomena that are qualitatively different from those of Hermitian systems and have been exploited to achieve a number of ends, including the generation of exceptional points, nonreciprocal dynamics, non-orthogonal normal modes, and topological operations. However to date these effects have only been accessible with nearly-degenerate modes (i.e., modes with frequency difference comparable to their linewidth and coupling rate). Here we demonstrate an optomechanical scheme that extends topological control to highly non-degenerate modes of a non-Hermitian system. Specifically, we induce a "virtual exceptional point" between two mechanical modes whose frequencies differ by >10^3 times their linewidth and coupling rate, and use adiabatic topological operations to transfer energy between these modes. This scheme can be readily implemented in many physical systems, potentially extending the utility of non-Hermitian dynamics to a much wider range of settings.