A team of researchers from MIT, Harvard University and the University of Belgrade has found a way to make photons repel each other inside a cloud of ultracold atomic gas. In their paper published in the journal Nature Physics, the group describes experiments they conducted that involved coupling pairs of photons to atomic states and what they learned from them.
Source:
https://phys.org/news/2020-06-method-photons-repel-ultracold-atomic.html