Implications of the low-temperature instability of dynamical mean-field theory for double-exchange systems

Article

关键词: TO-POLARON CROSSOVER;    INFINITE DIMENSIONS;    PHASE-SEPARATION;    MAGNETORESISTANCE;    TRANSITION;   

DOI  :  10.1103/PhysRevB.72.245112

来源: SCIE

【 摘 要 】

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.

【 授权许可】

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