Excitations magnétiques quantiques dans les rayures des supraconducteurs à oxyde de cuivre.

Quantum magnetic excitations from stripes in copper oxide superconductors.

Auteurs : TRANQUADA J. M., WOO H., PERRING T. G., et al.

Type d'article : Article

Résumé

In the copper oxide parent compounds of the high-transition-temperature superconductors the valence electrons are localized-one per copper site by strong intra-atomic Coulomb repulsion. A symptom of this localization is antiferromagnetism, where the spins of localized electrons alternate between up and down. Superconductivity appears when mobile 'holes' are doped into this insulating state, and it coexists with antiferromagnetic fluctuations. In one approach to describing the coexistence, the holes are believed to self-organize into 'stripes' that alternate with antiferromagnetic (insulating) regions within copper oxide planes, which would necessitate an unconventional mechanism of superconductivity. There is an apparent problem with this picture, however: measurements of magnetic excitations in superconducting near optimum doping are incompatible with the naive expectations for a material with stripes. The authors report neutron scattering measurements on stripe-ordered. The authors show that the measured excitations are, surprisingly, quite similar. They find instead that the observed spectrum can be understood within a stripe model by taking account of quantum excitations. Their results support the concept that stripe correlations are essential to high-transition-temperature superconductivity.

Détails

  • Titre original : Quantum magnetic excitations from stripes in copper oxide superconductors.
  • Identifiant de la fiche : 2004-2697
  • Langues : Anglais
  • Source : Nature - vol. 429 - n. 6991
  • Date d'édition : 03/06/2004
  • Document disponible en consultation à la bibliothèque du siège de l'IIF uniquement.

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