Entanglement generation in the ultra-strongly coupled Rabi model

TL;DR

This paper investigates how ultra-strong coupling in the quantum Rabi model enables the generation of maximally entangled Bell states between two qubits, providing analytical and numerical insights into the dynamics beyond the rotating wave approximation.

Contribution

It offers analytical solutions for the system's dynamics in the ultra-strong coupling regime and explores the validity of these results beyond the slow-qubit approximation.

Findings

Analytical expressions for entanglement generation in the ultra-strong coupling regime.

Numerical validation of the model beyond the slow-qubit approximation.

Identification of conditions for optimal Bell state creation.

Abstract

We analyze the dynamics of the quantum Rabi model for two qubits interacting through a common bosonic field mode (resonator), focusing on the generation and detection of maximally entangled Bell states. We obtain analytical results for the unitary dynamics of this system in the slow-qubit (or degenerate) regime, considering ultra-strong coupling between qubits and resonator mode, for which the rotating wave approximation is no longer applicable. We also numerically investigate the dynamics beyond the slow-qubit condition in order to study the validity of the model in the presence of less strict conditions.