Symplectic large-N theory of topological heavy-fermion semiconductors
Department of Physics, Kent State University,
Received in final form: 22 May 2012
Published online: 5 September 2012
I present a theory of topological heavy-fermion semiconductors based on the large-N symplectic representation for the electron spin. The theory is exact in the limit when the number of spin flavors N = 2k is infinite. I find that both weak and strong topological insulating phases exist for k < 3. Furthermore, for k ≥ 3 the weak topological insulating state is fully suppressed while only strong topological and trivial insulator states survive. In addition, using the mean-field theory results, I consider the tunneling into topologically trivial and non-trivial phases of a generic heavy-fermion insulators by calculating the differential tunneling conductance. The implications of the presented results for the existing heavy-fermion semiconductors are discussed.
Key words: Solid State and Materials
© EDP Sciences, Società Italiana di Fisica and Springer-Verlag, 2012