We have studied the photoexcited carrier relaxation dynamics in the Kondo insulator SmB6 and the heavy fermion metal YbAgCu4 as a function of temperature and excitation level. The dynamic response is found to be both strongly temperature dependent and nonlinear. The data are analyzed with a Rothwarf-Taylor bottleneck model, where the dynamics are governed by the presence of a narrow gap in the density of states near the Fermi level. The remarkable agreement with the model suggests that carrier relaxation in a broad class of heavy electron systems (both metals and insulators) is governed by the presence of a (weakly temperature dependent) hybridization gap.
@article{arxiv.cond-mat/0512108,
title = {Photoexcited electron dynamics in Kondo insulators and heavy fermions},
author = {Jure Demsar and Verner K. Thorsmolle and John L. Sarrao and Antoinette J. Taylor},
journal= {arXiv preprint arXiv:cond-mat/0512108},
year = {2009}
}
Comments
accepted for publication in Physical Review Letters