Chaotic speckle: a pattern resulting from light being scrambled by a complex medium such as multimode optical fiber. (Courtesy: M Malik and S Goel)
Topics: Entanglement, Quantum Optics, Quantum Mechanics
Natalia Herrera-Valencia and colleagues have successfully unscrambled entangled light after it has passed through a 2 m long multimode fiber. Led by Mehul Malik, the team at the Heriot-Watt University in Edinburgh tackled the challenge using entanglement itself. The research was done in collaboration with a colleague at the University of Glasgow and is described in a recent paper in Nature Physics.
Light passing through a disordered (or “complex”) medium like atmospheric fog or a multimode fiber gets scattered, albeit in a known manner. As a result, the information carried by the light gets distorted but is preserved, and extra steps are needed to access it. This gets especially tricky for the transport of entangled states of light because the medium muddles up the quantum correlations. The states get “scrambled” and “unscrambling” becomes necessary to retrieve the original entangled states.
Entangled light is unscrambled using entanglement itself, Lavanya Taneja, Physics World