2004/09/12 by Priya Mahadevan, Alex Zunger, D. D. Sarma +1
Materials Science · Physics and Astronomy · #Condensed matter physics #Exchange interaction #Ferromagnetism #Limit (mathematics) #Magnetic and transport properties of perovskites and related materials #Magnetic properties of thin films #Magnetic semiconductor #Magnetism #Materials science #Physics #Quantum mechanics #RKKY interaction #Semiconductor #ZnO doping and properties #cond-mat.other
paper · pdf · doi:10.1103/physrevlett.93.177201
4 pages (5 figures); To appear in Phys. Rev. Lett
arxiv created 2004/09/12 · openalex publication_date 2004/10/18 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Ferromagnetism in Mn-doped GaAs, the prototypical dilute magnetic semiconductor (DMS), has so far been attributed to hole mediated RKKY-type interactions. First-principles calculations reveal a strong direction dependence of the ferromagnetic (FM) stabilization energy for Mn pairs, a dependence that cannot be explained within RKKY. In the limit of a hostlike hole engineered here where the RKKY model is applicable, the exchange energies are strongly reduced, suggesting that this limit cannot explain the observed ferromagnetism. The dominant contribution stabilizing the FM state is found to be maximal for 110-oriented Mn pairs and minimal for 100-oriented Mn pairs, providing an alternate explanation for magnetism in such materials in terms of energy lowering due to p-d hopping interactions, and offering a new design degree of freedom to enhance FM.