Giant atom with disorders: Effects from imperfect couplings

TL;DR

This paper investigates how disorder in coupling positions and strengths affects giant atom phenomena, finding robustness in the Markovian regime but increased sensitivity in the non-Markovian regime, especially for coupling positions.

Contribution

It provides a detailed analysis of disorder effects on giant atom phenomena, highlighting the importance of precise control in non-Markovian regimes for observing oscillating BICs.

Findings

Giant-atom phenomena are robust to disorder in the Markovian regime.

Non-Markovian regime is more sensitive to disorder, especially in coupling positions.

Higher precision in coupling position control is required to observe non-Markovian effects.

Abstract

The study of giant atoms goes beyond the local interaction paradigm in the conventional quantum optics, and predicts novel phenomena, such as oscillating bound states in the continuum (BICs) and decoherence-free interaction (DFI) that do not exist in small atoms, for some particular parameter settings of coupling positions and strengths. However, in the realistic experiments to implement giant-atom systems, there is always some level of disorder both in coupling positions and strengths. In this work, we investigate the effects of disorder on the phenomena related to giant atoms. We find that the giant-atom related phenomena are robust to both disorders of coupling positions and strengths in the Markovian regime, but more sensitive to the disorder of coupling positions in the non-Markovian regime. Our work shows that, to observe the non-Markovian phenomenon such as (oscillating) BICs in giant-atom systems, more precision is needed to control the disorder of coupling positions than that of the coupling strengths in the experiments.