Abstract
We present a theory of carrier-induced ferromagnetism in diluted magnetic semiconductors ( ) which allows for arbitrary itinerant-carrier spin polarization and dynamic correlations. Both ingredients are essential in identifying the system's elementary excitations and describing their properties. We find a branch of collective modes, in addition to the spin waves and Stoner continuum which occur in metallic ferromagnets, and predict that the low-temperature spin stiffness is independent of the strength of the exchange coupling between magnetic ions and itinerant carriers. We discuss the temperature dependence of the magnetization and the heat capacity.
- Received 24 January 2000
DOI:https://doi.org/10.1103/PhysRevLett.84.5628
©2000 American Physical Society