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Distinct charge and spin gaps in underdoped YBa2Cu3O7-x

D. Mihailovic·V. V. Kabanov·K. Zagar·J. Demsar
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Abstract

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.

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D. Mihailovic, V. V. Kabanov, K. Zagar, J. Demsar. 1999-07-13. Distinct charge and spin gaps in underdoped YBa2Cu3O7-x. https://doi.org/10.1103/physrevb.60.r6995

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