The distribution of entanglement between separated nodes of a quantum network is a fundamental task for almost all quantum communication and quantum information processing applications. While optical photons are the only way to distribute quantum states over very large distances, for on-chip communication microwave photons or even propagating phonons, i.e., quantized sound waves, can also be used for this task. Our goal is to find more and more efficient ways to interface these information carriers with superconducting qubits or spin-based quantum memories, and to develop new protocols for a fast and robust distribution of entanglement across large-scale quantum networks.

One of the questions we study is how microwave photons can be created and distributed in a network of chiral waveguides to entangle distant qubits. We study several strategies, such as using parametric amplifiers to produce pairs of entangled photons, which are in turn used to entangle the qubits, or filtering an input thermal source to create a Non-Markovian reservoir. 

Another topic is how the coupling between superconducting qubits and a waveguide can be modulated in time to maximize the fidelity of emission and state transfert. In particular, we design numerical tools to study these processes in the ultrastrong coupling regime, where standard approximation break down and new physical effects emerge.

People: Przemyslaw Zielinski, Adrian Parra-Rodriguez, Philipe Gigon, Louis Garbe, Aliya Batool

Related publications:

Entangling remote qubits through a two-mode squeezed reservoir, A.Andrés-Juanes et al., arXiv:2510.07139 (2025)

Non-Markovian thermal reservoirs for autonomous entanglement distribution, J. Agusti et al., arXiv:2506.20742 (2025)