Interaction between free electrons (IMAGE) The University of Hong Kong Caption Researchers from HKU, MIT and other universities have come up with an innovative way to foster interactions between photons and electrons. The findings are recently published in Nature. The artistic illustration above is the interaction between free electrons and flat bands of a photonic crystal slab. Credit Lei CHEN Usage Restrictions N/A License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.