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Effective Hamiltonian for Ga_{1-x}Mn_xAs in the Dilute Limit

Gregory A. Fiete·Gergely Zarand·Kedar Damle
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Abstract

We derive an effective Hamiltonian for ${\rm Ga}_{1-x}{\rm Mn}_x {\rm As}$ in the dilute limit, where ${\rm Ga}_{1-x}{\rm Mn}_x {\rm As}$ can be described in terms of spin $F=3/2$ polarons hopping between the {\rm Mn} sites and coupled to the local {\rm Mn} spins. We determine the parameters of our model from microscopic calculations. Our approach treats the large Coulomb interaction in a non-perturbative way, captures the effects of spin-orbit coupling and disorder, and is appropriate for other p-doped magnetic semiconductors. Our model applies to uncompensated {\rm Mn} concentrations up to $x \sim 0.03$.

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Gregory A. Fiete, Gergely Zarand, Kedar Damle. 2003-07-22. Effective Hamiltonian for Ga_{1-x}Mn_xAs in the Dilute Limit. https://doi.org/10.1103/physrevlett.91.097202

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