Valleytronics (IMAGE) DOE/Lawrence Berkeley National Laboratory Caption A study has shown that the optical Stark effect, which describes the energy shift in a two-level system induced by a non-resonant laser field, can be used to control valley excitons in MX2 semiconductors. Credit Image courtesy of Feng Wang, Berkeley Lab Usage Restrictions None License Licensed 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.