Ground state splitting of ^8S rare earth ions in semiconductors

TL;DR

This paper introduces a new mechanism for ground state splitting in ^8S rare earth ions within semiconductors, emphasizing the roles of intra-atomic interactions, spin-orbit effects, and hybridization with valence bands, with numerical examples in PbTe.

Contribution

It presents a novel mechanism for ground state splitting involving multiple interactions and compares it with existing models, supported by numerical calculations in PbTe.

Findings

Splitting depends on 5d level position relative to band structure

Hybridization significantly influences ground state splitting

Numerical results demonstrate the model's applicability in PbTe

Abstract

We propose a new mechanism leading to the ground state splitting for the rare earth ^8S ions in semiconductor crystals. The resulting splitting is due to three effects, the first is the intra atomic 4f-5d spin-spin interaction, the second one is the spin - orbit interaction for 5d electrons and the third one is their hybridization with the valence band states of semiconductors host. The resulting splitting significantly depends on the relative position of 5d level with respect to semiconductor host band structure. We also discuss different model, already known in the literature, which is also based on ion - band states hybridization. For both models, as an example, we present results of numerical calculations for rare earth ion in IV-VI semiconductor PbTe.