Implications of the Low-Temperature Instability of Dynamical Mean Theory for Double Exchange Systems

Abstract

The single-site dynamical mean field theory approximation to the double exchange model is found to exhibit a previously unnoticed instability, in which a well-defined ground state which is stable against small perturbations is found to be unstable to large-amplitude but purely local fluctuations. The instability is shown to arise either from phase separation or, in a narrow parameter regime, from the presence of a competing phase. The instability is therefore suggested as a computationally inexpensive means of locating regimes of parameter space in which phase separation occurs.

arXiv comment5 pages 5 figures

References in corpus (6)

• Complexity in Strongly Correlated Electronic Systems
• Phase Separation in Electronic Models for Manganites
• On the Fermi Liquid to Polaron Crossover II: Double Exchange and the Physics of "Colossal" Magnetoresistance
• On the Fermi Liquid to Polaron Crossover I: General Results
• T=0 Phase Diagram of the Double-Exchange Model
• Phase separation in double exchange systems

Cited by in corpus (3)

• Dynamical Mean Field Study of Model Double-Exchange Superlattices
• The ground state magnetic phase diagram of the ferromagnetic Kondo-lattice model
• On the Possibility of Ferromagnetism and Half-Metallicity in Local Moment Systems