Entanglement made tangible

EPFL scientists have designed a first-ever experiment for demonstrating quantum entanglement in the macroscopic realm. Unlike other such proposals, the experiment is relatively easy to set up and run with existing semiconductor devices.

Quantum entanglement refers to the "pairing" of two subatomic particles in such a way that they form a whole quantum system. Interest in entanglement is increasing today, as it challenges the foundations of quantum mechanics itself, and is also key for achieving quantum information processing and communication. Entanglement is thought to exist up to the everyday, or "macroscopic" realm – according to the predictions of quantum physics – but experimental proposals to show this often involve conditions that are difficult to achieve in today's labs. Publishing in Physical Review Letters, scientists at EPFL have put forward an experimental protocol for demonstrating QE at the macroscopic scale by using a device that can be controlled by light. Unlike others, the protocol can be carried out with relative ease, using state-of-the-art nanostructures that are already available in several laboratories worldwide. This perspective can propel our understanding of the quantum world towards unexpected directions.