2009/06/04 by Aakash Pushp, Colin V. Parker, Colin Parker +8 · 4 citations
Materials Science · Physics and Astronomy · #Iron-based superconductors research #Magnetic and transport properties of perovskites and related materials #Physics of Superconductivity and Magnetism #cond-mat.str-el #cond-mat.supr-con
paper · pdf · doi:10.1126/science.1174338
To appear in Science express on June 04, 2009. http://www.sciencemag.org/cgi/content/abstract/1174338
arxiv created 2009/06/04 · openalex publication_date 2009/06/05 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/31
Understanding the mechanism by which d wave superconductivity in the cuprates emerges and is optimized by doping the Mott insulator is one of the major outstanding problems in condensed-matter physics. Our high-resolution scanning tunneling microscopy measurements of the high-transition temperature (Tc) superconductor Bi2Sr2CaCu2O8+delta show that samples with different Tc values in the low doping regime follow a remarkably universal d wave low-energy excitation spectrum, indicating a doping-independent nodal gap. We demonstrate that Tc instead correlates with the fraction of the Fermi surface over which the samples exhibit the universal spectrum. Optimal Tc is achieved when all parts of the Fermi surface follow this universal behavior. Increasing the temperature above Tc turns the universal spectrum into an arc of gapless excitations, whereas overdoping breaks down the universal nodal behavior.