Many-body breakdown of indirect gap in topological Kondo insulators

TL;DR

This paper demonstrates that incorporating nonlocal correlations in a variational wave function can describe topological and trivial insulating phases, their transition to metallic states, and captures key features of Kondo semiconductors.

Contribution

It introduces a method that accounts for nonlocal correlations in a variational wave function to study topological Kondo insulators, capturing phase transitions and topological properties.

Findings

Successfully describes topologically trivial and nontrivial insulating phases.

Captures the transition from insulator to metal with gap closure.

Represents key features observed in Kondo semiconductors.

Abstract

We show that the inclusion of nonlocal correlation effects in a variational wave function for the ground state of a topological Anderson lattice Hamiltonian is capable of describing both topologically trivial insulating phases and nontrivial ones characterized by an indirect gap, as well as its closure at the transition into a metallic phase. The method, though applied to an oversimplified model, thus captures the metallic and insulating states that are indeed observed in a variety of Kondo semiconductors, while accounting for topologically nontrivial band structures.