Ferromagnetism and transport in diluted magnetic semiconductors

This dissertation focuses on the study of ferromagnetism in Dilute Magnetic Semiconductors. To study these strongly correlated electronic systems, two non- perturbative techniques are used: the Dynamical Mean Field Approximation (DMFA) and the Dynamical Cluster Approximation (DCA). The model used for Dilute Magnetic Semiconductors (DMS) incorporates the strong spin-orbit couplings of the carrier holes as found in most III-V semiconductors doped with manganese such as Ga_1-xMn_xAs. Calculated within the DMFA, the spin-orbit coupling effects give rise to various interesting physics, primarily the anisotropic behavior of the impurity band that affect the charge transport properties in the ferromagnetic phase. We show that non-local correlations, within the DCA, are responsible for magnetic frustration and magnetic reorientation of the DMS. The DMFA is employed to study ferromagnetism and transport in Ga_1-xMn_xAs, using the sp³ tight-binding Hamiltonian. Finally, employing the sp³ tight-binding Hamiltonian and the DMFA, ferromagnetism in a wide band gap Ga_1-xMn_xN is studied.

Name thesis:degree_name

Doctor of Philosophy (PhD)

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Physical Sciences and Mathematics

Grantor

Physics and Astronomy

Year dc:date.available

2010

Author dc:creator

• Nili, Abdolmadjid

• Magnetic Semiconductors
• Dynamical Mean Field Approximation
• Dynamical Cluster Approximation

Statement dc:rights

• unrestricted
• Release the entire work immediately for access worldwide.

Identifier

etd-07072010-160348
https://repository.lsu.edu/gradschool_dissertations/955

OAI identifier oai:identifier

oai:repository.lsu.edu:gradschool_dissertations-1954