A systamatic quantitative comparison of ''pseudogap'' values obtained from the analysis of charge and spin excitation spectroscopies in underdoped YBa2Cu3O7-x using a temperature-independent gap shows two distinct excitations, one visible in spin-flip spectroscopies like NMR and spin polarized neutron scattering, and the other in charge excitation spectoscopies like single particle tunneling and time-resolved quasiparticle relaxation. Both appear to decrease with doping x approximately as 1/x and are T-independent, existing above and below Tc. We suggest that the charge excitation can be attributed to a pair-breaking local gap, while the spin excitation can be explained by an intra-gap local triplet state.
@article{arxiv.cond-mat/9907005,
title = {Distinct charge and spin gaps in underdoped YBa2Cu3O7-x},
author = {D. Mihailovic and V. V. Kabanov and K. Zagar and J. Demsar},
journal= {arXiv preprint arXiv:cond-mat/9907005},
year = {2008}
}
Comments
4 pages and 3 postscript figures, to be published in Phys. Rev.B (Rapid. Comm), Figure 1 is corrected