Quantum entanglement experiment. Quantum physicist Robert Ursin in a tunnel under the River Danube during a quantum entanglement experiment. Entanglement is a property of a pair of particles in which a change to one has an instantaneous effect on the other, no matter how far apart they are. Researchers at Vienna University, Austria, split an entangled photon pair, and sent each photon to a different receiver. They travelled down one of the wires at left. Entanglement was confirmed by the detectors. It is hoped that this entanglement will find uses in cryptography, quantum computing and satellite communications. The team repeated the test with photons in air.