"To produce the effect, the researchers use photon polarization. Then, they produced two different kinds of time-reversal breaking. They used fiber optics to pr

"To produce the effect, the researchers use photon polarization. Then, they produced two different kinds of time-reversal breaking. They used fiber optics to produce two types of gauge fields that affected the geometric phases of the optical waves, first by sending them through a crystal biased by powerful magnetic fields, and second by modulating them with time-varying electrical signals, both of which break the time-reversal symmetry. They were then able to produce interference patterns that revealed the differences in how the light was affected when sent through the fiber-optic system in opposite directions, clockwise or counterclockwise..." Lordy, I with these folks would speak english, but no, whats really important is saying things in a way only others in your field can comprehend. You can actually comprehend papers written even just 50 years ago because they written to be understood, not to confuse the granting body. TL;DR: they setup a laser interferometer and twiddled the light in different ways through each path, the resulting interference pattern was evidence of the effect claimed. On one path they polarized the light by running it through an LCD (a "crystal biased by powerful magnetic fields"). On the other path I'm less sure what they mean by "time-varying electrical signals", probably just means they were effectively pulsing it on and off. And somehow, by running each path through opposing winds of a fiber optic system they think they are getting results indicating "time reversal". I'll have to take them on their word on that, that's where I know less about the subject matter.