Towards a topological phase diagram for SmB₆ alloys

SmB₆ is a strongly correlated material that has been attributed as a topological insulator and a Kondo insulator. The bulk insulating character of SmB₆ is surprisingly robust against nominal carrier doping, however the robustness of the band topology picture within alloys is less clear. I will present angle resolved photoemission measurements that characterize the loss of topological band structure features as a function of carrier doping and decoherence in Eu- and Ce- alloyed samples. Topologically associated features are observed out to unprecedented 30% Eu and 50% Ce concentrations. These properties are interpreted in the context of a recent re-designation of the conduction band, and provide the bases to propose a new low energy heirarchy of electronic symmetries involved in the insulating gap and topological surface states.