Magnetic Field Effect in an Extended Periodic Anderson Model with Dynamical Mean-Field Theory

We investigate effect of an external magnetic field h in an extended periodic Anderson model, which includes the repulsion U c f between f and conduction electron in a usual periodic Anderson model. We treat the model with dynamical mean-field theory using an exact diagonalization method. Applying a magnetic field, the first-order valence transition (FOVT) occurs at the smaller U c f and shallower f -electron level e f , at which a jump of the magnetization m occurs simultaneously. The position of the quantum critical point (QCP) of the FOVT is shifted to the region of the smaller U c f and shallower e f level as h increases. For large h the position of the QCP does not changed in the (e f - h /2)– U c f plane.