Temperature and Field Dependence of Multipolar Excitations in CeB₆

Abstract

We study the temperature and field dependence of multipolar excitations in CeB₆ within RPA theory for the dynamical susceptibility. It is shown that the destruction of AFQ order at constant field close to T_Q(H) should lead to a collapse of the high energy part of the excitation spectrum. In the disordered state above T_Q(H) the dispersions show a qualitative change due to the vanishing multipolar order parameters. We also study the field dependence of excitations at constant temperature and compare with experimental results obtained at the X(001) point. In the low temperature T<<T_Q and intermediate to high field regime H≥T_Q we compare the results to those of the extended Holstein Primakoff (HP) approach and find complete agreement.