Photoexcited electron dynamics in Kondo insulators and heavy fermions.
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.
Jozef Stefan Institute, Jamova 39, SI-1000, Ljubljana, Slovenia.
Jure
J
Demsar
Verner K
VK
Thorsmølle
John L
JL
Sarrao
Antoinette J
AJ
Taylor