Topological excitations in the Kondo insulator candidate YbB12

Recently, tremendous attention has been devoted to the discovery of new class of materials, known as topological insulator. Topological insulators have insulating bulk properties while their surface states are conducting, and protected by time-reversal symmetry. Topological insulators are interesting from a fundamental perspective due to their unusual electronic band structures and may end up with useful applications to the field of spintronics. In this proposal, we plan to investigate the physics of YbB12, a candidate Kondo topological insulator where Kondo hybridization of the localized f electrons with the conductive electronic bulk band is responsible for band-inversion. To confirm such scenario, we propose to use inelastic neutron scattering to study the electronic band excitations of this material, and determine whether YbB12 is topologically non-trivial.