2007/08/17 by R. Khasanov, S. Strässle, D. Di Castro +6 · 4 citations
Engineering · Mathematics · Physics and Astronomy · #Condensed matter physics #Cuprate #Geometry #Homogeneous space #Inflection point #Lambda #London penetration depth #Mathematics #Order (exchange) #Penetration depth #Physics #Physics of Superconductivity and Magnetism #Quantum mechanics #Superconducting Materials and Applications #Superconductivity #Superconductivity in MgB2 and Alloys #Symmetry (geometry) #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevlett.99.237601
published as Phys. Rev. Lett. 99, 237601 (2007) · 5 pages, 3 figures
arxiv created 2007/08/17 · openalex publication_date 2007/12/06 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The temperature dependence of the London penetration depth \ensuremathλ was measured for an untwinned single crystal of YBa2Cu3O_7\ensuremath-\ensuremathδ along the three principal crystallographic directions (a, b, and c). Both in-plane components (\ensuremathλa^\ensuremath-2 and \ensuremathλb^\ensuremath-2) show an inflection point in their temperature dependence which is absent in the component along the c direction (\ensuremathλc^\ensuremath-2). The data provide convincing evidence that the in-plane superconducting order parameter is a mixture of (s+d)-wave symmetry whereas it is mainly s wave along the c direction. In conjunction with previous results it is concluded that coupled s+d-order parameters are universal and intrinsic to cuprate superconductors.