Regensburg 2016 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 96: Magnetic Semiconductors
HL 96.3: Vortrag
Freitag, 11. März 2016, 10:00–10:15, H13
Effective Spin Models and Critical Temperatures for Diluted Magnetic Semiconductors. — Richard Bouzerar1, •Daniel May2, Ute Löw2, Denis Machon1, Patrice Melinon1, and Georges Bouzerar1 — 1Institut Lumière Matière, CNRS et Université Lyon 1, 69622 Villeurbanne Cedex, France — 2Technische Universität Dortmund, Lehrstuhl für Theoretische Physik II, 44221 Dortmund, Germany
Diluted magnetic semiconductors (DMS) are materials where magnetic ions substitute a small percentage of the host’s cations. We use a one-band VJ model with three adjustable parameters to describe DMS and extract long-range spin-spin couplings. These couplings are subsequently used as input to a classical Heisenberg model which is studied by Monte Carlo simulation (MC) and a self-consistent approach based on Green’s functions (L-RPA). Both methods treat random lattice configurations beyond the standard Mean Field Approximation and without resorting to an effective medium. Our focus lies mainly on (In,Mn)P for small concentrations x<0.1 of manganese where critical temperatures of 20-40 K are expected. The L-RPA provides us with a self-consistent expression for Tc whereas we use finite size scaling for the MC results to calculate a reliable critical temperature. Our goal is to provide a consistent description of recent experimental results for the magnetic properties of the Mn-doped InP diluted magnetic semiconductor.