Inhaltszusammenfassung

We present a theoretical survey of ferromagnetic transition temperatures in cubic (iii,mn)v semiconductors based on a model with s=5/2 local moments exchange coupled to itinerant holes in the host semiconductor valence band. starting from the simplest mean-field theory of this model, we estimate the t-c enhancement due to exchange and correlation in the itinerant-hole system and the t-c suppression due to collective fluctuations of the ordered moments. we show that high critical temperatures ...We present a theoretical survey of ferromagnetic transition temperatures in cubic (iii,mn)v semiconductors based on a model with s=5/2 local moments exchange coupled to itinerant holes in the host semiconductor valence band. starting from the simplest mean-field theory of this model, we estimate the t-c enhancement due to exchange and correlation in the itinerant-hole system and the t-c suppression due to collective fluctuations of the ordered moments. we show that high critical temperatures in these ferromagnetic semiconductors require both the large magnetic susceptibility contribution from the valence-band heavy holes and the large spin stiffness resulting from a complex valence-band structure that includes the more dispersive light holes. our calculations demonstrate that the model of carrier-induced ferromagnetism of these systems is consistent with high critical temperatures observed experimentally in (iii,mn)v semiconductors.» weiterlesen» einklappen

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Klassifikation

DFG Fachgebiet:
3.17 - Theoretische Chemie

DDC Sachgruppe:
Physik