Shifting of the magnetic resonance peak to lower energy in the superconducting state of underdoped YBa_2Cu_3O_{6.8}

Ph. Bourges; L. P. Regnault; Y. Sidis; J. Bossy; P. Burlet; C. Vettier; J. Y. Henry; M. Couach

doi:10.1209/epl/i1997-00244-6

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Shifting of the magnetic resonance peak to lower energy in the superconducting state of underdoped YBa_2Cu_3O_{6.8}

Ph. Bourges·L. P. Regnault·Y. Sidis·J. Bossy·P. Burlet·C. Vettier·J. Y. Henry·M. Couach

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Abstract

Inelastic neutron scattering has been used to determine the dynamic spin fluctuations in an underdoped high temperature superconductor YBCO_{6.8} single crystal. The magnetic resonance, that occurs around 40 meV in overdoped samples, is shifted to a lower energy, E_r= 34 meV. A constant ratio, $E_r/ k_B T_C= 4.9 \pm 0.2$, 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.

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Ph. Bourges, L. P. Regnault, Y. Sidis, J. Bossy, P. Burlet, C. Vettier, J. Y. Henry, M. Couach. 1997-04-11. Shifting of the magnetic resonance peak to lower energy in the superconducting state of underdoped YBa_2Cu_3O_{6.8}. https://doi.org/10.1209/epl%2Fi1997-00244-6

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