Quantum interference and controllable magic cavity QED via a giant atom in coupled resonator waveguide

TL;DR

This paper explores how a giant atom coupled to a coupled resonator waveguide exhibits quantum interference effects, enabling controllable cavity-like behavior with potential applications in waveguide QED experiments.

Contribution

It introduces a novel magic cavity model using a giant atom, demonstrating controllable transition between perfect and leaky cavities, which is not possible in traditional setups.

Findings

Giant atom population exhibits oscillations and photon trapping due to interference.

Proposes a controllable magic cavity model based on giant atom dynamics.

Effects are experimentally accessible in current waveguide QED setups.

Abstract

We study the Markovian and Non-Markovian dynamics in a giant atom system which couples to a coupled resonator waveguide (CRW) via two distant sites. Under certain conditions, we find that the giant atom population can exhibit an oscillating behavior and the photon can be trapped in the giant atom regime. These phenomena are induced by the interference effect among the bound states both in and outside the continuum. As an application of the photon trapping, we theoretically propose a magic cavity model where the giant atom serve as either a perfect or leaky cavity, depending on the distance between the coupling sites. The controllability of the magic cavity from perfect to leaky one can not be realized in the traditional cavity or circuit QED setup. The predicted effects can be probed in state-of-the-art waveguide QED experiments and provide a striking example of how the different kinds of bound states modify the dynamics of quantum open system in a structured environment.