Observation of vortices and hidden pseudogap from scanning tunneling spectroscopic studies of the electron-doped cuprate superconductor Sr0.9La0.1CuO2M. L. Teague1, A. D. Beyer1, M. S. Grinolds1, S. I. Lee2 and N.-C. Yeh1
1 Department of Physics, California Institute of Technology - Pasadena, CA 91125, USA
2 National Creative Research Initiative Center for Superconductivity, Department of Physics, Sogang University Seoul, Korea 121-742
received 2 September 2008; accepted in final form 27 November 2008; published January 2009
published online 7 January 2009
We present the first demonstration of vortices in an electron-type cuprate superconductor, the highest Tc(=43 K) electron-type cuprate Sr0.9La0.1CuO2. Our spatially resolved quasiparticle tunneling spectra reveal a hidden low-energy pseudogap inside the vortex core and unconventional spectral evolution with temperature and magnetic field. These results cannot be easily explained by the scenario of pure superconductivity in the ground state of high-Tc superconductivity.
74.50.+r - Tunneling phenomena; point contacts, weak links, Josephson effects.
74.25.Op - Mixed states, critical fields, and surface sheaths.
74.72.Jt - Other cuprates, including Tl- and Hg-based cuprates.
© EPLA 2009