Symplectic large-N theory of topological heavy-fermion semiconductors

TL;DR

This paper develops a large-N symplectic theoretical framework for topological heavy-fermion semiconductors, revealing the existence and suppression of different topological phases and analyzing tunneling conductance characteristics.

Contribution

It introduces a novel large-N symplectic approach to analyze topological phases in heavy-fermion semiconductors, providing exact results in the infinite-N limit.

Findings

Existence of weak and strong topological insulating phases for certain parameters

Suppression of weak topological insulators for higher N values

Analysis of tunneling conductance in different topological phases

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>2 the weak topological insulating state 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.