Physicists confirm 20-year-old theory that could boost quantum technology

Key Points:

• Physicists at the Institute of Science and Technology Austria (ISTA) have experimentally realized a fully autonomous method for distributed entanglement between distant qubits using a "quantum bath" of correlated light particles, confirming a 20-year-old theoretical prediction.
• Unlike traditional methods that rely on active control and repeated measurements, the ISTA approach stabilizes entangled states remotely and continuously via a common source of correlated microwave photons, making entanglement always available on demand.
• The prototype device uses microwave photons to synchronize two distant qubits, demonstrating a new ground state stabilized by a continuous stream of correlated photons, which could potentially be scaled to synchronize multiple qubits.
• Validation of the entangled qubit states was achieved through quantum tomography, allowing the team to probe the qubits' superposition states with high temporal resolution.
• Although the current method transfers about 10% of the bath’s entanglement and is less efficient than active control methods, it opens new possibilities for scalable quantum processors and quantum optics experiments toward fault-tolerant quantum computing.