T. Mutou et Ds. Hirashima, GAP FORMATION IN THE SYMMETRICAL PERIODIC ANDERSON MODEL IN INFINITE DIMENSIONS .2., Journal of the Physical Society of Japan, 64(12), 1995, pp. 4799-4812
We study dymanical properties of the symmetric periodic Anderson model
in infinite dimensions by applying the quantum Monte Carlo method and
the maximum entropy method. It is found that at low temperatures a ga
p is developed in the density of states, in the local spin excitation
spectrum and in the local charge excitation spectrum. We clarify the e
ffects of the strong electron correlation on structure of these dynami
cal quantities. As the strength of interaction increases, a sharp peak
evolves al a low frequency region in the spin excitation spectrum whi
le a broad shoulder appears at a higher frequency. On the other hand,
as the interaction gets strong, the charge excitation spectrum splits
into a low-frequency part and a high-frequency part; the low frequency
part is severely suppressed by the interaction. The reliability and t
he limitation of the maximum entropy method are also discussed in deta
il.