Valence fluctuations in an extended periodic anderson model under a magnetic field

Abstract

We investigate effect of an external magnetic field h in an extended periodic Anderson model (ePAM), which includes the repulsion Ucf between f and conduction electron in a usual periodic Anderson model. We study the ePAM with dynamical mean-field theory (DMFT) using an exact diagonaliztion method at finite temperature. Applying magnetic field, the first-order valence transition occurs at the smaller Ucf and shallower ϵf, at which a jump of the magnetization m occurs simultaneously. The present result is consistent with the result of the slave–boson mean-field theory, but the previous result overestimates the first-order valence transition.