2004/01/31 by J. M. Tranquada, H. Woo, T. G. Perring +7 · 5 citations
Physics and Astronomy · #Advanced Condensed Matter Physics #Magnetic properties of thin films #Physics of Superconductivity and Magnetism #cond-mat.str-el #cond-mat.supr-con
paper · pdf · doi:10.1038/nature02574
published as Nature 429, 534 (2004) · 11 pages, including 4 figures; revised version (rewritten abstract, text shortened, some changes to references, part of Fig. 4 eliminated)
arxiv created 2004/04/09 · openalex publication_date 2004/06/01 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
In the copper-oxide parent compounds of the high-transition-temperature superconductors, the valence electrons are localized, one per copper site, due to strong intraatomic Coulomb repulsion. A symptom of the localization is antiferromagnetism, where the spins of localized electrons alternate between up and down. The superconductivity appears when mobile 'holes' are doped into this insulating state, and it coexists with antiferromagnetic fluctuations. In one approach to the coexistence, the holes are believed to self-organize into 'stripes' that alternate with antiferromagnetic (insulating) regions within copper-oxide planes. Such an unusual electronic state would necessitate an unconventional mechanism of superconductivity. There is an apparent problem with this picture, however: measurements of magnetic excitations in superconducting YBa(2)Cu(3)O(6+x) near optimum doping are incompatible with the naive expectations for a material with stripes. Here we report neutron scattering measurements on stripe-ordered La(1.875)Ba(0.125)CuO(4). We show that the measured excitations are, surprisingly, quite similar to those in YBa(2)Cu(3)O(6+x) (i.e., the predicted spectrum of magnetic excitations is wrong). We find instead that the observed spectrum can be understood within a stripe model by taking account of quantum excitations. Our results support the concept that stripe correlations are essential to high-transition-temperature superconductivity.