A Tale of Two Emergent Phenomena: From Pseudogap to Negative Electronic Compressibility, and Back Again?

A central theme of modern condensed matter physics is to understand old and discover new emergent phenomena in quantum materials. These phenomena emerge through the collective behavior of electrons due to their mutual interactions (correlations). In this talk, I will share with you my unique experience as to how discoveries are made, often in a serendipitous manner, in related research. The pseudogap phenomena have been a quarter-century mystery in condensed matter physics. Our search of these phenomena in iridium oxides has led to the discovery of 3D negative electronic compressibility. We found this new emergent phenomenon is driven by the electron correlations intimately connected with the pseudogap phenomena. Both phenomena in the iridium oxide are shown to derive from a special insulating phase in a way that resembles the classic metal-insulator transitions seen on the 2D electron/hole gases in semiconductor heterostructures. - Pizza and drinks will be provided during the event.