Precision measurements of the temperature dependence of λ in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi mathvariant="normal">YBa</mi></mrow><mrow><mn>2</mn></mrow></msub></mrow></math><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi mathvariant="normal">Cu</mi></mrow><mrow><mn>3</mn></mrow></msub></mrow></math><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi mathvariant="normal">O</mi></mrow><mrow><mn>6.95</mn></mrow></msub></mrow></math>: Strong evidence for nodes in the gap function

W. N. Hardy; D. A. Bonn; D. C. Morgan; Ruixing Liang; Kuan Zhang

doi:10.1103/PhysRevLett.70.3999

Precision measurements of the temperature dependence of λ in ${YBa}_{2}$ ${Cu}_{3}$ $O_{6.95}$ : Strong evidence for nodes in the gap function

W. N. Hardy, D. A. Bonn, D. C. Morgan, Ruixing Liang, and Kuan Zhang

Phys. Rev. Lett. 70, 3999 – Published 21 June 1993

Abstract

A miniature superconducting resonator operating at 1.3 K and 900 MHz has been used to measure the change in λ(T) from 1.3 K to $T_{c}$ in very high quality single crystals of ${YBa}_{2}$ ${Cu}_{3}$ $O_{6.95}$ . The data, which have a resolution of 1-2 Å, show a strong linear term extending from approximately 3 to 25 K. We believe the strong linear dependence to be characteristic of the pure system and that its apparent absence in thin films and some crystals is due to the presence of defects.