Exotic collective behaviors of giant quantum emitters in two-dimensional baths

TL;DR

This paper investigates the complex collective behaviors of giant quantum emitters in two-dimensional baths, revealing unconventional dynamics, controllable emission patterns, and persistent interactions that advance quantum network engineering.

Contribution

It introduces a nonperturbative analysis of giant atoms in 2D baths, demonstrating engineered quantum dynamics, controllable emission, and persistent interactions in higher-dimensional environments.

Findings

Unconventional quantum dynamics with non-Markovian beats and bound states.

Controllable photon emission directions via phase engineering.

Coherent dipole interactions persist despite continuum coupling.

Abstract

Nonlocal light-matter interactions with giant atoms in high-dimensional environments are not only fundamentally intriguing for testing quantum electrodynamics beyond the dipole approximation but also crucial for building high-dimensional quantum networks and engineering multipartite entangled states. Given the enigmatic and largely uncharted collective signatures exhibited by multiple giant atoms within two-dimensional optical baths, we delve into their nonperturbative collective dynamics within the single-excitation subspace, focusing on the case where they are coupled to a common two-dimensional photonic reservoir and employing a resolvent operator approach. We demonstrate that precisely engineered atomic arrangements lead to unconventional quantum dynamics, featuring non-Markovianity-induced beats and long-lived bound states in the continuum, thereby providing a versatile platform for implementing two-dimensional quantum memory. Phenomenologically, we observe the emergence of exotic photon emission patterns in both two- and three-dimensional (3D) baths. The emission directions are shown to be precisely controllable on demand through exact phase engineering of the coupling parameters, enabling a highly efficient chiral light-matter interface. Moreover, our generalization to a 3D bath reveals that coherent dipole-dipole interactions can survive despite the coupling to a continuum of modes, a finding that challenges conventional wisdom regarding decoherence.