Driven-dissipative preparation of remote entanglement in chiral waveguide quantum electrodynamics*

Stabilizing entanglement between remote qubits is of fundamental interest, and a crucial resource for quantum networks. A dissipatively stabilizing protocol, such as that proposed by Stannigel et al. [1] could relax a pair of driven qubits coupled through a nonreciprocal waveguide into an entangled steady state. It has been shown that coupling more qubits in a chain configuration to each pair generates a steady state consisting of independent Bell pairs of remotely entangled qubits [2]. We study this system under conditions achievable with superconducting circuits and find that in addition to offering a more experimentally viable route toward stabilized remote entanglement, an additional pair of qubits may be more entangled than the first pair. Inspired by the exact analytical results derived in [2], we show in particular how the second pair of qubits in the chain can be more entangled than a single pair, and what limits the maximum achievable concurrence. Our results offer a deeper understanding of the dissipative dynamics of this system, and show that it is a promising route toward stabilizing entanglement between remote superconducting qubits.

[1]: K Stannigel et al 2012 New J. Phys. 14 063014 

[2]: A Lingenfelter et al 2023 https://arxiv.org/abs/2307.09482