Abstract
Material design of GaN-based ferromagnetic diluted magnetic semiconductors is given based on ab initio calculations within the local spin density approximation. The electronic structure of 3d-transition-metal-atom-doped GaN was calculated by the Korringa-Kohn-Rostoker method combined with the coherent potential approximation. It was found that the ferromagnetic ground states were readily achievable in V-, Cr- or Mn-doped GaN without any additional carrier doping treatments. A simple explanation on the systematic behavior of the magnetic states in GaN-based diluted magnetic semiconductors is also given.