Transition Temperature of a Magnetic Semiconductor with Angular Momentum j

Abstract

We employ dynamical mean-field theory to identify the materials properties that optimize Tc for a generalized double-exchange (DE) model. We reach the surprising conclusion that Tc achieves a maximum when the band angular momentum j equals 3/2 and when the masses in the 1/2 and 3/2 sub-bands are equal. However, we also find that Tc is significantly reduced as the ratio of the masses decreases from one. Consequently, the search for dilute magnetic semiconductors (DMS) materials with high Tc should proceed on two fronts. In semiconductors with p bands, such as the currently studied Mn-doped Ge and GaAs semiconductors, Tc may be optimized by tuning the band masses through strain engineering or artificial nanostructures. On the other hand, semiconductors with s or d bands with nearly equal effective masses might prove to have higher Tc's than p-band materials with disparate effective masses.

arXiv comment5 pages, 4 figures

References in corpus (17)

• Spintronics: Fundamentals and applications
• Ferromagnetic Semiconductors: Moving Beyond (Ga,Mn)As
• On the Fermi Liquid to Polaron Crossover II: Double Exchange and the Physics of "Colossal" Magnetoresistance
• High Curie temperature GaMnAs obtained by resistance-monitored annealing
• Highly enhanced Curie temperatures in low temperature annealed (Ga,Mn)As epilayers
• On the Fermi Liquid to Polaron Crossover I: General Results
• High Temperature Ferromagnetism in GaAs-based Heterostructures with Mn Delta Doping
• Transition temperature of ferromagnetic semiconductors: a dynamical mean field study
• Magnetic Transition Temperature of (La,Sr)MnO${}_3$
• Temperature Dependence of the Conductivity in (La,Sr)MnO${}_3$
• Ellipsometric study of the Electronic Structure of GaMnAs and LT-GaAs
• Magnetic phase diagram of the Hubbard model
• Ferromagnetic transition in a double-exchange system
• Ferromagnetic transition in a double-exchange system containing impurities
• Dynamical mean field theory for transition temperature and optics of CMR manganites
• Spin Diffusion in Double-Exchange Manganites
• Ferromagnetic transition in a double-exchange system containing impurities in the Dynamical Mean Field Approximation

Cited by in corpus (5)

• Impurity Band Conduction in a High Temperature Ferromagnetic Semiconductor
• Origin of the anomalous magnetic circular dichroism spectral shape in ferromagnetic (Ga,Mn)As: Impurity bands inside the band gap
• Dynamics of Impurity and Valence Bands in GaMnAs within the Dynamical Mean Field Approximation
• A single layer of Mn in a GaAs quantum well: a ferromagnet with quantum fluctuations
• Nonlocal effects on magnetism in the diluted magnetic semiconductor Ga_{1-x}Mn_{x}As