Institute of Science and Technology Austria researchers demonstrate autonomous quantum entanglement

Researchers at the Institute of Science and Technology Austria (ISTA) have demonstrated a new method for creating distributed entanglement between physically separated qubits using a “quantum bath.” This autonomous approach, published in Physical Review X, provides the first experimental validation of a theoretical concept proposed over two decades ago.

Unlike previous methods that rely on active control, repeated measurements, or post-selection to entangle distant qubits, this technique uses a continuous stream of correlated photons to stabilize an entangled state. This allows the qubits to synchronize automatically without active measurement interventions. The team, led by PhD student Alejandro Andrés-Juanes and professor Johannes Fink, utilized microwave photons to couple the qubits with the entangled photon source, a method compatible with existing superconducting-qubit technologies.

While the prototype successfully demonstrates the concept, it currently transfers approximately 10 percent of the bath’s available entanglement, making it less efficient than active control methods. However, the ability to connect widely separated modules through autonomous entanglement could serve as a foundation for building larger quantum computers and future quantum networks.