Non-Markovian giant-atom dynamics in a disordered lattice

TL;DR

This paper investigates how disorder affects the non-Markovian dynamics of giant atoms coupled to photonic lattices, revealing robustness in some properties and enhancement of memory effects due to disorder.

Contribution

It introduces a disorder-aware framework analyzing the impact of lattice disorder on giant-atom non-Markovian feedback and coherence properties.

Findings

Population decay remains robust against moderate disorder.

Non-Markovian memory can be significantly enhanced by disorder.

Spectral features like bound states are sensitive to disorder.

Abstract

While ideal lattice models have been widely used to study giant-atom systems, fabrication-induced defects inevitably introduce disorder in realistic platforms. Here, we study non-Markovian dynamics of a giant atom coupled to a discrete photonic lattice with on-site frequency disorder. Using time-domain and spectral analyses, we show that the overall population-decay envelope and global photon-transport patterns remain robust against moderate lattice disorder, while the quantified non-Markovian memory can be significantly enhanced within the explored disorder range. We characterize the memory using a normalized geometrical non-Markovianity measure tailored to delayed giant-atom feedback and demonstrate how the coupling-point separation and the disorder strength serve as complementary parameters that shape the delay timescale and the complexity of coherent-feedback interference. Spectral analysis reveals that scattering-band transport is relatively insensitive to disorder, whereas disorder-sensitive bound-state branches and localization features reshape revival windows and promote information backflow. Our results establish a disorder-aware framework for understanding and engineering non-Markovian feedback effects of giant atoms in structured reservoirs.