The Underlying Intermediate Valence in SmB6
Samarium hexaboride (SmB6) has long been labeled an intermediate valent compound, with the caveat that its electrical conductivity remains finite at low temperatures. This apparent discrepancy has been resolved over the last several years due in no small part to research at UMD. Now SmB6 appears to be the best candidate material to embody a topological Kondo insulator state, although aspects of the underlying f-electron interactions have not been completely established.
In this talk, I’ll describe our recent x-ray spectroscopic measurements that show that the intermediate valent state in SmB6 cannot be tuned away easily by pressure, making it unlike any known intermediate valent material. I’ll discuss what this might have to do with topological states.