Electronic noise of diluted magnetic semiconductor (Ga,Mn)As around Curie point

Abstract

We have studied the spontaneous fluctuation noise spectrum of （Ga,Mn）As in frequency domian from 1 kHz to 250 kHz. We found that the electronic noise can be reduced by a magnetic field and its magnitude increases with increasing temperature of the （Ga,Mn）As sample. The electrical noise spectra at different frequencies have different temperature dependence and their amplitude changes at the phase transition temperature, suggesting that the phase transition process of （Ga,Mn）As is subtly different from normal magnetic materials. Our results may help understanding the origin of magnetism in （Ga,Mn）As.