Antiferromagnetic correlations in superconducting YBa2Cu3O6+x samples from optical absorption data; comparison with the results of neutron and muon experiments

• Published in: Low temperature physics (Woodbury, N.Y.) N.Y.), 2003-12, Vol.29 (12), p.982-992
• Main Authors: Samovarov, V. N., Vakula, V. L., Libin, M. Yu
• Format: Article
• Language: English
• ISSN: 1063-777X; 1090-6517
• DOI: 10.1063/1.1630713

Narrow-band spectral features demonstrating a high sensitivity to the development of the pseudogap state are detected in metallic films of YBa2Cu3O6+x with Tc≈51 and 74 K. Attention is focused on the temperature behavior of the exciton–bimagnon band A+3J (≈2.15 eV) and the exciton–two-magnon band A+4J (≈2.28 eV); these bands arise as a result of phase separation into insulating and metallic regions. By comparing the optical results with published data on the temperature behavior of the muon depolarization rate and the integrated intensity of the (π,π) magnetic resonance it is shown for the first time that all three independent techniques give the same observed temperature dependence f(T/Tc) of measured quantities both in the normal and superconducting states. The established correlation of the optical, neutron, and muon data is analyzed from the standpoint of the formation of stripe ordering and the compatibility of antiferromagnetic order and superconductivity.