Non-perturbative $J_{pd}$ model and ferromagnetism in dilute magnets

Abstract

We calculate magnetic couplings in the $J_{pd}$ model for dilute magnets, in order both to identify the relevant parameters which control ferromagnetism and also to bridge the gap between first principle calculations and model approaches. The magnetic exchange interactions are calculated non-perturbatively and disorder in the configuration of impurities is treated exacly, allowing us to test the validity of effective medium theories. Results differ qualitatively from those of weak coupling. In contrast to mean field theory, increasing $J_{pd}$ may not favor high Curie temperatures: $T_C$ scales primarily with the bandwidth. High temperature ferromagnetism at small dilutions is associated with resonant structure in the p-band. Comparison to diluted magnetic semiconductors indicate that Ga(Mn)As has such a resonant structure and thus this material is already close to optimality.

4 pages, 4 Figures

References in corpus (11)

• Theory of ferromagnetic (III,Mn)V semiconductors
• Prospects of high temperature ferromagnetism in (Ga,Mn)As semiconductors
• Model for vacancy-induced d${}^0$ ferromagnetism in oxide compounds
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• Calculating the Curie Temperature reliably in diluted III-V ferromagnetic semiconductors
• Why RKKY exchange integrals are inappropriate to describe ferromagnetism in diluted magnetic semiconductors
• Magnetic Percolation and the Phase Diagram of the Disordered RKKY model
• Compensation, interstitial defects and ferromagnetism in diluted semiconductors
• Insulator-Metal Phase Diagram of the Optimally Doped Manganites from the Disordered Holstein-Double Exchange Model
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Cited by in corpus (18)

• Experimental probing of the interplay between ferromagnetism and localisation in (Ga,Mn)As
• A family of high-temperature ferromagnetic monolayers with locked spin-dichroism-mobility anisotropy: MnNX and CrCX (X=Cl, Br, I; C=S, Se, Te)
• Hole states in wide band-gap diluted magnetic semiconductors and oxides
• Observation of strong-coupling effects in a diluted magnetic semiconductor (Ga,Fe)N
• Exchange constant and domain wall width in (Ga,Mn)(As,P) films with self-organization of magnetic domains
• Unified picture for diluted magnetic semiconductors
• Enhanced Curie temperature and skyrmion stability in room temperature ferromagnetic semiconductor CrISe monolayer
• Carrier induced ferromagnetism in the insulating Mn doped III-V semiconductor InP
• Optical conductivity of Mn doped GaAs
• Response properties of III-V dilute magnetic semiconductors: interplay of disorder, dynamical electron-electron interactions and band-structure effects
• Magnetic spin excitations in Mn doped GaAs : A model study
• Determination of the Fermi Level Position in Dilute Magnetic Ga${}_{1-x}$Mn${}_x$N Films
• Robustness of flat band superconductivity against disorder in a two-dimensional Lieb lattice model
• Effective Heisenberg exchange integrals of diluted magnetic semiconductors determined within realistic multi-band tight-binding models
• Metal-insulator transition induced by fluctuations of the magnetic potential in semiconductors with magnetic impurities
• Comment on the PRL "Large-Scale Monte Carlo Study of a Realistic Lattice Model for Ga_(1-x)Mn_xAs"
• Curie temperatures of the concentrated and diluted Kondo-lattice model as a possible candidate to describe magnetic semiconductors and metals
• On the reliability of recent Monte Carlo studies of dilute systems of localized spins interacting with itinerant carriers