Two-photon entanglement in multi-qubit bi-directional waveguide QED

TL;DR

This paper explores how two-photon Gaussian wavepackets can generate and control entanglement among multiple qubits in bi-directional waveguide QED, highlighting effects of system parameters and non-linearities.

Contribution

It introduces methods to enhance and store entanglement using chirality, decay rates, and two-photon interactions in multi-qubit waveguide QED systems.

Findings

Entanglement increases with more qubits.

Two-photon interactions enable non-linear entanglement control.

Chirality and decay rates significantly enhance entanglement storage.

Abstract

We study entanglement generation and control in bi-directional waveguide QED driven by a two photon Gaussian wavepacket. In particular, we focus on how increasing the number of qubits affects the overall average pairwise entanglement in the system. We also investigate how the presence of a second photon can introduce non-linearities, thereby manipulating the generated entanglement. In addition, we show that through the introduction of chirality and small decay rates, entanglement can be stored and enhanced up to factors of 2 and 3, respectively. Finally, we analyze the influence of finite detunnings and time-delays on the generated entanglement.