Eur. Phys. J. B (2012) 85: 297
https://doi.org/10.1140/epjb/e2012-30318-5

Regular Article

Symplectic large-N theory of topological heavy-fermion semiconductors

Department of Physics, Kent State University, Kent OH 44240, USA

^a e-mail: mdzero@kent.edu

Received: 13 April 2012
Received in final form: 22 May 2012
Published online: 5 September 2012

Abstract

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.