Unconventional and robust light-matter interactions based on the non-Hermitian skin effect

TL;DR

This paper explores how non-Hermitian lattice models with the skin effect enable robust, unconventional light-matter interactions, revealing mechanisms for decoherence-free dynamics and potential applications in quantum engineering.

Contribution

It introduces a novel analysis of light-matter interactions in non-Hermitian systems, highlighting the robustness and amplification mechanisms for giant emitters within the Hatano--Nelson and bosonic Kitaev models.

Findings

Giant emitters exhibit decoherence-free dynamics despite dissipation.

Non-Hermiticity and self-interference enable protection from dissipation.

Robust light-matter interactions are achievable in non-Hermitian topological systems.

Abstract

Lattice models featuring the non-Hermitian skin effect have attracted rapidly growing interest due to their nontrivial spectral topology and the exotic field dynamics they enable. Such non-Hermitian lattices provide a promising paradigm for engineering exotic light-matter interactions which benefit from the intrinsic chirality and unconventional (non-Bloch) band theory. Here we study a series of unconventional light-matter interactions between quantum emitters and the prototypical Hatano--Nelson model, and briefly discuss the case with an extended lattice model dubbed the bosonic Kitaev chain. We focus on the robustness of the dynamics against various imperfections and elucidate the underlying mechanisms. We consider both small emitters, which interact with the lattice at single sites, and giant emitters coupling at multiple sites. The latter exhibit an exclusive amplification mechanism, which we find enables decoherence-free dynamics even in the presence of extra dissipation in the system. The protection from dissipation arises from the cooperation of the non-Hermiticity and the self-interference effect, and is therefore lacking for small emitters. These results not only provide deeper insights into the interplay of non-Hermiticity and various interference effects, but also have potential applications in engineering exotic spin Hamiltonians and quantum networks.