Noncommutative Aharonov-Bohm Effect as time reversal signal achieved for first time in laboratory!

noncommutative), where the sequence in which the field is applied matters. The latter are more difficult to realize in solid-state systems, but recent theoretical work has suggested that these could be synthesized optically. Yang et al. generated non-Abelian gauge fields by cascading multiple nonreciprocal optical elements and verified this accomplishment by the observed interference patterns in a Sagnac interferometer.

https://science.sciencemag.org/content/365/6457/1021

 The Aharonov-Bohm Effect, named after the theorists who predicted it in 1959, confirmed that gauge fields — beyond being a pure mathematical aid — have physical consequences.

 In addition, the non-Abelian gauge fields that the group was able to synthesize produced a non-Abelian Berry phase, and “combined with interactions, it may potentially one day serve as a platform for fault-tolerant topological quantum computation,” he says.

So it's the Taiji symbol!! Amazing https://scitechdaily.com/exotic-physics-phenomenon-involving-time-reversal-observed-for-first-time/

 Particles placed inside an Abelian (commutative) gauge field can acquire different phases when traveling along the same path in opposite directions, as is evident from the Aharonov-Bohm effect.

  the observation of the non-Abelian Aharonov-Bohm effect with classical waves and classical fluxes. On the basis of optical mode degeneracy, we break time-reversal symmetry in different manners, via temporal modulation and the Faraday effect, to synthesize tunable non-Abelian gauge fields. The Sagnac interference of two final states, obtained by reversely ordered path integrals, demonstrates the noncommutativity of the gauge fields. Our work introduces real-space building blocks for non-Abelian gauge fields, relevant for classical and quantum exotic topological phenomena.

 So now let's read the actual research paper...

Yang, Y., Peng, C., Zhu, D., Buljan, H., Joannopoulos, J. D., Zhen, B., & Soljačić, M. (2019). Synthesis and observation of non-Abelian gauge fields in real space. Science, 365(6457), 1021–1025. doi:10.1126/science.aay3183 

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Exotic physics phenomenon is observed for first time

Observation of the predicted non-Abelian Aharonov-Bohm Effect may offer step toward fault-tolerant quantum computers.

http://news.mit.edu/2019/aharonov-bohm-effect-physics-observed-0905?fbclid=IwAR2MCkwcDzBzA43418VbrlQ5Wq11x9qGe98vc0K6uLuJyu1UblWN8lnfEhw

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. Without the breaking of time-reversal invariance, the beams should have been identical, but instead, their interference patterns revealed specific sets of differences as predicted, demonstrating the details of the elusive effect.