An ab initio Local Exchange Approach to the Calculations of Tc of Dilute Magnetic Semiconductors

TL;DR

This paper presents an ab initio local exchange method to calculate the Curie temperature of dilute magnetic semiconductors, specifically GaMnAs, using DFT and Anderson impurity models, achieving results consistent with experiments.

Contribution

It introduces a multiscale ab initio approach combining DFT and impurity models to accurately predict Tc in dilute magnetic semiconductors.

Findings

Calculated Tc of GaMnAs agrees with experimental data.

Identified hybridization of Mn 3d states with the valence band.

Discussed the role of Hubbard parameters in DFT calculations.

Abstract

The DFT calculations were performed of densities of states of semiconductor GaAs and magnetic semiconductor Ga0.9375Mn0.0625As. It is obtained that a part of Mn3d- states is hybridized with valence band at Fermi level. The exchange integrals of Anderson impurity model were calculated making use of atomic Hartree-Fock package and angular momentum coupling technique. Theoretical Tc of Ga0.9375Mn0.0625As obtained in the multiscale ab initio method is in reasonable agreement with experiment. The application of Hubbard parameters in DFT calculations using ultrasoft pseudopotentials is discussed.