Correlation effects in the density of states of annealed GaMnAs
arXiv:cond-mat/0605753 · doi:10.1103/PhysRevB.75.033308
Abstract
We report on an experimental study of low temperature tunnelling in hybrid NbTiN/GaMnAs structures. The conductance measurements display a root mean square V dependence, consistent with the opening of a correlation gap in the density of states of GaMnAs. Our experiment shows that low temperature annealing is a direct empirical tool that modifies the correlation gap and thus the electron-electron interaction. Consistent with previous results on boron-doped silicon we find, as a function of voltage, a transition across the phase boundary delimiting the direct and exchange correlation regime.
arXiv commentReplaced with revised version. To appear in Phys. Rev. B
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