Magnetic Circular Dichroism Studies of Carrier-Induced Ferromagnetism in(Ga1−xMnx)As

Abstract

Magnetic circular dichroism is used to investigate the evolution of ferromagnetism in the $p$-type magnetic semiconductor $\left({\mathrm{Ga}}_{1-x}{\mathrm{Mn}}_x\right)\mathrm{As}$. Local Mn moments and holes produce two spectroscopically distinct contributions, whose properties reveal an antiferromagnetic Mn-hole alignment in the ferromagnetic state. These components are present in both metallic and insulating samples with different temperature and field dependences, suggesting that the holes play a more active role in mediating the ferromagnetic exchange than in traditional RKKY systems.