MAGNETO-TRANSPORT AND MAGNETO-OPTICAL PROPERTIES OF FERROMAGNETIC (III,Mn)V SEMICONDUCTORS: A REVIEW

Abstract

Rapid developments in material research of metallic ferromagnetic (III,Mn)V semiconductors over the past few years have brought a much better understanding of these complex materials. We review here some of the main developments and current understanding of the bulk properties of these systems within the metallic regime, focusing principally on the magneto-transport and magneto-optical properties. Although several theoretical approaches are reviewed, the bulk of the review uses the effective Hamiltonian approach, which has proven useful in describing many of these properties namely in (Ga,Mn)As and (In,Mn)As. The model assumes a ferromagnetic coupling between Mn d-shell local moments mediated by holes in the semiconductor valence band.

Anomalous Hall effect in a two-dimensional Dirac band: The link between the Kubo-Streda formula and the semiclassical Boltzmann equation approach

“…1 Theoretical descriptions of the dc AHE invariably involve long and complex calculations and usually do not lead to simple general results with transparent interpretations. [1][2][3][4] Theories of the AHE normally focus on particular simple model Hamiltonians, and ignore interactions apart from mean-field exchange potentials that encode magnetic order.…”

“…1 Theoretical descriptions of the dc AHE invariably involve long and complex calculations and usually do not lead to simple general results with transparent interpretations. [1][2][3][4] Theories of the AHE normally focus on particular simple model Hamiltonians, and ignore interactions apart from mean-field exchange potentials that encode magnetic order. Even with these simplifications, the AHE problem tends to be difficult because the effect usually follows mainly from density-matrix linear response that is off-diagonal in Bloch state band indices, i.e., from induced interband coherence rather than simply from changes in Bloch state occupations.…”

Transport theory for disordered multiple-band systems: Anomalous Hall effect and anisotropic magnetoresistance

“…Nevertheless, theoretical description of the AHE is far from being complete and it often involves cumbersome calculations without transparent interpretations. 14 The difficulties appear due to the necessity to consider the off-diagonal elements in Bloch band indices ͑the interband coherences induced by charge currents͒. There is a general trend to focus on particular simple models in order to overcome the common mistakes that are made in treating the AHE.…”

Anomalous Hall effect in insulatingGa1−xMnxAs

“…1,2 Recently, the Berry phase mechanism of AHE in ferromagnetic semiconductors has been proposed by Jungwirth et al 3 following the initial idea given by Karplus and Luttinger 4 that the AHE in ferromagnets is caused by intrinsic spin-orbit interaction. Ga 1-x Mn x As is the most thoroughly investigated "workhorse" material used for the study of ferromagnetic properties of diluted magnetic semiconductors.…”