Topological Phase Diagram of the System (IMAGE) Forschungsverbund Berlin Caption The direction of rotation of the light (green for circular clockwise, purple for circular anticlockwise) maps the topological phase diagram of the system, distinguishing between its trivial phase (above the black curve) and its topological phase (below the black curve). Credit Illustration: MBI Usage Restrictions The image may only be used with appropriate caption and credit. 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.