Character of states near the Fermi level in (Ga,Mn)As: Impurity to valence band crossover
Character of states near the Fermi level in (Ga,Mn)As: Impurity to valence band crossover
We discuss the character of states near the Fermi level in Mn-doped GaAs, as revealed by a survey of dc transport and optical studies over a wide range of Mn concentrations. A thermally activated valence-band contribution to dc transport, a midinfrared peak at energy $\ensuremath{\hbar}\ensuremath{\omega}\ensuremath{\approx}200\phantom{\rule{0.3em}{0ex}}\mathrm{meV}$ in the ac conductivity, and …