Researchers achieve autonomous entanglement of distant qubits using a quantum bath

A collaboration led by Alejandro Andrés-Juanes and Johannes Fink at the Institute of Science and Technology Austria has built a prototype that uses a shared environment of correlated microwave photons to autonomously generate and maintain entanglement between two spatially separated qubits. By treating the surrounding quantum bath as the source of entanglement, the system creates a new ground state that stabilizes the qubits’ joint state even after their individual coherence would normally decay.

The experiment, published in Physical Review X, confirms a prediction made more than 20 years earlier and offers a simpler alternative to existing schemes that rely on active photon control and repeated measurements. Although the current transfer of entanglement is roughly 10 % of the bath’s capacity, the researchers see potential for scaling the method to synchronize many distant qubits, which is essential for building larger quantum computers and networks.

The work also highlights challenges that delayed earlier attempts, such as reproducing idealized theoretical conditions in the laboratory. Future developments may improve efficiency and integrate optical photons for long-distance quantum communication.