Physics – Condensed Matter – Materials Science
Scientific paper
2010-01-17
Phys. Rev. B 81, 054401 (2010)
Physics
Condensed Matter
Materials Science
25 figures
Scientific paper
We employ a kinetic-exchange tight-binding model to calculate the magnetic interaction and anisotropy energies of a pair of substitutional Mn atoms in GaAs as a function of their separation distance and direction. We find that the most energetically stable configuration is usually one in which the spins are ferromagnetically aligned along the vector connecting the Mn atoms. The ferromagnetic configuration is characterized by a splitting of the topmost unoccupied acceptor levels, which is visible in scanning tunneling microscope studies when the pair is close to the surface and is strongly dependent on pair orientation. The largest acceptor splittings occur when the Mn pair is oriented along the <110> symmetry direction, and the smallest when they are oriented along <100>. We show explicitly that the acceptor splitting is not simply related to the effective exchange interaction between the Mn local moments. The exchange interaction constant is instead more directly related to the width of the distribution of all impurity levels -- occupied and unoccupied. When the Mn pair is at the (110) GaAs surface, both acceptor splitting and effective exchange interaction are very small except for the smallest possible Mn separation.
Canali Carlo. M.
MacDonald Allan. H.
Strandberg Tor O.
No associations
LandOfFree
Magnetic interactions of substitutional Mn pairs in GaAs 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 Magnetic interactions of substitutional Mn pairs in GaAs, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Magnetic interactions of substitutional Mn pairs in GaAs will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-455706