Cavitylike strong coupling in macroscopic waveguide QED using three coupled qubits in the deep non-Markovian regime

TL;DR

This paper models a three-qubit waveguide QED system to emulate cavity-QED strong coupling, exploring non-Markovian effects, resonance tuning, and enhanced polariton lifetimes with advanced simulation techniques.

Contribution

It introduces a novel three-qubit waveguide QED setup that extends into the deep non-Markovian regime, revealing new control and resonance phenomena.

Findings

Significant enhancement of polariton lifetimes by orders of magnitude.

Ability to tune resonances and realize Fano-like features.

Demonstration of control using chiral probe qubits.

Abstract

We introduce a three qubit waveguide QED system to mimic the cavity-QED strong coupling regime of a probe qubit embedded in atom-like mirrors, which was realized in recent experiments. We then extend this system into the deep non-Markovian regime and demonstrate the profound role that retardation plays on the dressed resonances, allowing one to significantly improve the polariton lifetimes (by many orders of magnitude), tune the resonances, as well as realize Fano-like resonances and simultaneous coupling to multiple cavity modes. Exact Green function solutions are presented for the spectral resonances, and the quantum dynamics are simulated using matrix product states, where we demonstrate additional control of the cavity-QED system using chiral probe qubits.