Abstract
Inelastic neutron scattering has been used to determine the dynamic spin fluctuations in an underdoped high-temperature superconductor YBCO6.8 single crystal. The magnetic resonance, that occurs around 40 meV in overdoped samples, is shifted to a lower energy, Er = 34 meV. A constant ratio, Er/kBTC = 4.9 ± 0.2, almost independent of the doping level, is found. According to numerous theoretical approaches, this finding supports the idea that the resonance energy is proportional (approximately twice) to the superconducting gap.
Export citation and abstract BibTeX RIS