Abstract

Time-domain femtosecond pump-probe spectroscopy is applied to probe the low-energy single particle and collective excitations in a number of correlated electron systems. Two examples, which are chosen as representative of their respective classes of material are YBaCuO and K_0:3MoO₃ (Bluebronze). We will discuss the similarities and differences between the two systems, particularly their single-particle excitations. The development of models for the single-particle recombination^1;2 is found to be crucial for the understanding of the experiments, which then reveal some qualitatively new features in the low-energy spectra of these materials.

© 2000 IEEE