Ferromagnetic state in the one-dimensional Kondo lattice model

TL;DR

This paper demonstrates that the spin-selective Kondo insulator, a ferromagnetic state with a gap in minority electrons, exists in both one-dimensional and infinite-dimensional Kondo lattice models, indicating its generality.

Contribution

The study shows the realization of the spin-selective Kondo insulator in one dimension using DMRG, extending previous infinite-dimensional results and highlighting its ubiquity.

Findings

Spin-selective Kondo insulator observed in 1D model.

Mechanism is general across dimensions.

Supports ferromagnetic state's universal properties.

Abstract

In our recent study, Phys. Rev. Lett. 108 086402 (2012), we have revealed the intriguing properties of the ferromagnetic state in the Kondo lattice model with antiferromagnetic coupling in infinite dimensions: within the ferromagnetic metallic phase, the minority conduction electrons form a gap at the Fermi energy and do not participate in transport irrespective of interaction strength and filling. This half-metallic state is referred to as a spin-selective Kondo insulator. We here show that the spin-selective Kondo insulator can also be realized in the one-dimensional Kondo lattice model by studying static and dynamical quantities with the density matrix renormalization group. The emergence of the spin selective Kondo insulator both in one and infinite dimensions certainly demonstrates that this mechanism is quite general and ubiquitous for the ferromagnetic state in the Kondo lattice model irrespective of the dimensionality of the system.