A team of researchers from Xiamen University, the University of Ottawa and the University of Rochester has shown that it is possible to entangle photons with correlations between their radial and momentum states. In their paper published in the journal Physical Review Letters, the group describes experiments they carried out with entangled photons and what they learned.
Source:
https://phys.org/news/2019-08-entangled-photons-radial-position-momenta.html