A giant atom with modulated transition frequency

TL;DR

This paper investigates how dynamically modulating the transition frequency of a giant atom affects its spontaneous emission, revealing control over feedback effects and enabling chiral, tunable output fields for quantum technologies.

Contribution

It introduces a novel method of modulating giant atom transition frequencies to control emission dynamics and achieve tunable, chiral output fields.

Findings

Modulation suppresses retarded feedback, making the giant atom behave like a small one.

Dynamical phase from modulation alters feedback effects significantly.

Chiral and tunable temporal output profiles are achievable through phase control.

Abstract

Giant atoms are known for the frequency-dependent spontaneous emission and associated interference effects. In this paper, we study the spontaneous emission dynamics of a two-level giant atom with dynamically modulated transition frequency. It is shown that the retarded feedback effect of the giant-atom system is greatly modified by a dynamical phase arising from the frequency modulation and the retardation effect itself. Interestingly, such a modification can in turn suppress the retarded feedback such that the giant atom behaves like a small one. By introducing an additional phase difference between the two atom-waveguide coupling paths, we also demonstrate the possibility of realizing chiral and tunable temporal profiles of the output fields. The results in this paper have potential applications in quantum information processing and quantum network engineering.