(IMAGE) Yokohama National University Caption Professor Ikufumi Katayama of Yokohama National University (right) and Dr. Soungmin Bae of Tokyo Institute of Technology (left) co-led the research team that discovered the source of mysterious signals in two-dimensional semiconductor materials with the help of a coherent phonon spectrometer. Credit Yokohama National University Usage Restrictions News organizations may use or redistribute this image, with proper attribution, as part of news coverage of this paper only. 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.