Charting Bulk & Surface States in Correlated Insulators

This project explores a fascinating class of quantum materials called strongly (bulk) correlated insulators, in which electrons interact with one another so strongly that they can produce unexpected behavior. In some of these materials, for example, the interior is electrically insulating while the surface can still conduct electricity.

These conducting surface states are especially intriguing because they may provide a new platform for studying low-dimensional electronic systems. There is an exciting historical analogy: the discovery of graphene in the mid-2000s helped launch the rapidly growing field of two-dimensional and van der Waals materials. In a similar spirit, correlated insulators may offer a new route to low-dimensional physics—one in which the conducting layer emerges naturally at the surface of a three-dimensional material rather than being isolated as an atomically thin system.

Building on more than a decade of research on a well-known example, samarium hexaboride (SmB₆), our goal is to investigate a broader range of correlated insulators and determine which properties are common across different materials. By expanding the field beyond a few examples, we hope to establish correlated insulators as a broader platform for discovering new quantum phenomena and, hopefully, even for developing future electronic technologies.

This work is currently being funded by the National Science Foundation (NSF DMR-2532379).