The Birth of Topological Spintronics (IMAGE) Penn State Caption This illustration shows the crystal structure of the topological insulator bismuth selenide, Se-Bi-Se-Bi-Se, consisting of five atomic layers ('quinlayers') of alternating selenide (Se) and bismuth (Bi). Credit Samarth lab, Penn State University Usage Restrictions The image credit must be published along with the image. 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.