# Evidence of sp-d Exchange Interactions in CdSe Nanocrystals Doped with Mn, Fe and Co: Atomistic Tight-Binding Simulation

## TL;DR

This paper uses simulations to study how adding Mn, Fe, and Co to CdSe nanocrystals affects their electronic and magnetic properties under magnetic fields.

## Contribution

The study introduces atomistic tight-binding simulations to demonstrate sp-d exchange interactions in transition metal-doped CdSe nanocrystals.

## Key findings

- Spin splitting, Zeeman splitting, and magnetic polaron energies increase with applied magnetic fields and reach saturation.
- Electron spin-splitting and g-values follow the order Fe:CdSe > Mn:CdSe > Co:CdSe.
- Hole-related properties follow the order Co:CdSe > Fe:CdSe > Mn:CdSe.

## Abstract

Exploiting the atomistic tight-binding theory with the sp-d exchange term, the electronic and magnetic characteristics of CdSe nanoparticles embedded with Mn, Fe and Co are determined as a function of external magnetic fields to realize the sp-d exchange interactions. The transition metal species and applied magnetic fields are powerful factors to manipulate the electronic and magnetic characteristics of doped CdSe nanoparticles. With growing applied fields, the energies of spin splitting, Zeeman splitting and magnetic polaron improve and are assumed to reach saturation at high fields. All g-factor values are boosted in the presence of the external field and then fade with increasing applied fields. The electron spin-splitting energies and electron g values are ordered as Fe:CdSe > Mn:CdSe > Co:CdSe. The single-particle gaps, hole spin-splitting energies, Zeeman splitting energies and hole g values follow the order Co:CdSe > Fe:CdSe > Mn:CdSe.