Physics – Condensed Matter – Materials Science
Scientific paper
2005-03-16
Phys. Rev. B 72, 045212 (2005)
Physics
Condensed Matter
Materials Science
15 pages, 12 figures
Scientific paper
10.1103/PhysRevB.72.045212
We derive an effective Hamiltonian for ${\rm Ga}_{1-x}{\rm Mn}_x {\rm As}$ in the dilute limit, where ${\rm Ga}_{1-x}{\rm Mn}_x {\rm As}$ can be described in terms of spin $F=3/2$ polarons hopping between the {\rm Mn} sites and coupled to the local {\rm Mn} spins. We determine the parameters of our model from microscopic calculations using both a variational method and an exact diagonalization within the so-called spherical approximation. Our approach treats the extremely large Coulomb interaction in a non-perturbative way, and captures the effects of strong spin-orbit coupling and Mn positional disorder. We study the effective Hamiltonian in a mean field and variational calculation, including the effects of interactions between the holes at both zero and finite temperature. We study the resulting magnetic properties, such as the magnetization and spin disorder manifest in the generically non-collinear magnetic state. We find a well formed impurity band fairly well separated from the valence band up to $x_{\rm active} \lesssim 0.015$ for which finite size scaling studies of the participation ratios indicate a localization transition, even in the presence of strong on-site interactions, where $x_{\rm active}
Damle Kedar
Fiete Gregory A.
Moca Catalin Pascu
Zarand Gergely
No associations
LandOfFree
Disorder, spin-orbit, and interaction effects in dilute ${\rm Ga}_{1-x}{\rm Mn}_x{\rm As}$ does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Disorder, spin-orbit, and interaction effects in dilute ${\rm Ga}_{1-x}{\rm Mn}_x{\rm As}$, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Disorder, spin-orbit, and interaction effects in dilute ${\rm Ga}_{1-x}{\rm Mn}_x{\rm As}$ will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-568637