Temperature and field dependence of multipolar excitations in CeB6

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 much less than TQ and intermediate to high field regime H greater than or equal to T-Q we compare the results to those of the extended Holstein Primakoff (HP) approach and find complete agreement.