Photoinduced absorption from localized intra-gap states

Abstract

A model is developed for photoinduced absorption from localized states observed in femtosecond pump-probe experiments in high-Tc superconductors and other materials. The dynamics of localized carriers are described in terms of phenomenological approach similar to that originaly proposed by Rothwarf and Taylor. Expanding the relaxation rate in powers of the order parameter we have shown that density of localized carriers is sensitive to Tc. From the analysis of the experimental data on YBa2Cu3O(7-x) and K0.3MoO3 we conclude that significant intra-gap density of localized states exists in these materials. Temperature dependence of the density of photoexcited localized carriers in underdoped YBa2Cu3O(7-x) and in K0.3MoO3 is consistent with the observation of the pseudogap above Tc.

4 pages, 2 figures, acepted for publication in Physica C, invited poster presented at M2S, Feb. 20 - 25, 2000, Houston, USA

References in corpus (4)

• Quasiparticle relaxation dynamics in superconductors with different gap structures: theory and experiments on YBa_{2}Cu_{3}O_{7-δ}
• The superconducting gap Δ_{c}, the pseudogap Δ_{p} and pair fluctuations above Tc in overdoped YCaBaCuO from femtosecond time-domain spectroscopy
• Single particle and collective excitations in the one-dimensional charge density wave solid K0.3MoO3 probed in real time by femtosecond spectroscopy
• Carrier relaxation dynamics in intra-gap states: the case of the superconductor Y Ba_2 Cu_3O_7-delta and the charge-density-wave semiconductor K_0.3MoO_3