Unscrambling entanglement through a complex medium

Natalia Herrera Valencia, Suraj Goel, Will McCutcheon, Hugo Defienne, Mehul Malik

Research output: Contribution to journalArticlepeer-review

68 Citations (Scopus)
79 Downloads (Pure)


The transfer of quantum information through a noisy environment is a central challenge in the fields of quantum communication, imaging, and nanophotonics. In particular, high-dimensional quantum states of light enable quantum networks with significantly higher information capacities and noise robustness as compared with qubits. However, although qubit entanglement has been distributed over large distances through free space and fibre, the transport of high-dimensional entanglement is hindered by the complexity of the channel, which encompasses effects such as free-space turbulence or mode mixing in multimode waveguides. Here, we demonstrate the transport of six-dimensional spatial-mode entanglement through a 2-m-long, commercial multimode fibre with 84.4% fidelity. We show how the entanglement can itself be used to measure the transmission matrix of the complex medium, allowing the recovery of quantum correlations that were initially lost. Using a unique property of entangled states, the medium is rendered transparent to entanglement by carefully ‘scrambling’ the photon that did not enter it, rather than unscrambling the photon that did. Our work overcomes a primary challenge in the fields of quantum communication and imaging, and opens a new pathway towards the control of complex scattering processes in the quantum regime.
Original languageEnglish
Pages (from-to)1112-1116
Number of pages5
JournalNature Physics
Issue number11
Early online date3 Aug 2020
Publication statusPublished - Nov 2020

ASJC Scopus subject areas

  • General Physics and Astronomy


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