Quantum entanglement without transport: Leaky qubits offer route around noisy channels - Phys.org

What the report says

Phys.Org, citing a University of Illinois Grainger College of Engineering report, says researchers from the University of Illinois Urbana-Champaign and the University of Chicago have demonstrated a way to create quantum entanglement by using dissipation — the leakage of energy and information into the environment — rather than fighting it. The work, published in Physical Review X, used two superconducting qubits and a method the team calls “synthetic squeezing” to reproduce a long-discussed theoretical effect under laboratory conditions.

The experiment addresses a central challenge in quantum technology: entanglement is needed for quantum communication and computing, but it is easily damaged when delicate quantum states are moved through noisy or lossy channels. According to the report, the researchers used a cascaded quantum system in which qubits interact through a unidirectional waveguide and are externally driven so that the system relaxes into an entangled steady state.

Wolfgang Pfaff of Illinois led the Illinois side of the collaboration, while Aashish Clerk of the University of Chicago led the Chicago group. The article reports that synthetic squeezing helped compensate for imperfections that normally reduce entanglement quality in real-world cascaded systems, allowing the team to stabilize remote entanglement without physically transporting quantum particles in fragile states.

The groups are now looking at extending the approach beyond two qubits. The report says possible future directions include multiqubit systems, quantum computer networking without direct transmission of quantum information through noisy channels, and entanglement distillation, a process that could concentrate weaker entanglement into fewer, stronger entangled pairs.