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Critical Temperatures of a Two-Band Model for Diluted Magnetic Semiconductors

F. Popescu·Y. Yildirim·G. Alvarez·A. Moreo·E. Dagotto
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Abstract

Using Dynamical Mean Field Theory (DMFT) and Monte Carlo (MC) simulations, we study the ferromagnetic transition temperature Tc of a two-band model for Diluted Magnetic Semiconductors (DMS), varying coupling constants, hopping parameters, and carrier densities. We found that Tc is optimized at all fillings p when both impurity bands (IB) fully overlap in the same energy range, namely when the exchange couplings J and bandwidths are identical. The optimal Tc is found to be about twice larger than the maximum value obtained in the one-band model, showing the importance of multiband descriptions of DMS at intermediate J's.

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F. Popescu, Y. Yildirim, G. Alvarez, A. Moreo, E. Dagotto. 2006-01-25. Critical Temperatures of a Two-Band Model for Diluted Magnetic Semiconductors. https://doi.org/10.1103/physrevb.73.075206

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