In new work from our lab published in the journal Nature Physics, we demonstrate how high-dimensional entanglement can be transported through a complex medium consisting of a commercial multi-mode fibre supporting hundreds of spatial modes. This work was done in collaboration with Dr. Hugo Defienne from University of Glasgow.
In a quantum twist, the transmission matrix of the fibre was measured by mapping the entire matrix onto a single entangled state, which is an example of state-channel duality in quantum mechanics. Furthermore, the entanglement was regained without ever manipulating the fibre or the photon that entered it. Instead, we carefully scrambled the entangled partner that remained outside, allowing us to transport 6-dimensional entanglement through the fibre.
N. H. Valencia, S. Goel, W. McCutcheon, H. Defienne, & M. Malik, Unscrambling Entanglement through a Complex Medium, Nature Physics (2020), doi: 10.1038/s41567-020-0970-1.