MULTIBAND FEATURES AND TILTED VORTEX LATTICE IN THE SUPERCONDUCTOR -Bi2Pd

E. HERRERA; I. GUILLAMÓN; J. A. GALVIS; A. FENTE; A. CORREA; R. F. LUCCAS; F. J. MOMPEAN; M. GARCÍA- HERNANDEZ; S. VIEIRA; H. SUDEROW

El Escorial

Congreso; VORTEX 2015; 2015

We present scanning tunneling microscopy (STM) experiments at very low temperatures (150 mK) and tilted magnetic fields on single crystalline samples of the superconductor b-Bi2Pd. We have obtained high quality single crystals using solution growth method. We find surfaces showing the square atomic lattice and spatially homogeneous superconducting density of states following single gap s-wave BCS theory. The orientation ofthe vortex lattice with perpendicular magnetic fields observed up to Hc2(T) is locked to the square crystalline lattice. We find multiband features in the magnetic field dependence of the intervortex density of states and Hc2(T). We show how the mixed phase of superconductors is influenced by multiband features of the Fermi surface, even when the zero field gap structure follows single gap s-wave BCS theory.We use a homemade three axis superconducting magnet to study tilted vortex lattices in different azimuthal and polar orientations. We find that the structure of the tilted vortex lattice deviates with respect to expectations for isotropic superconductors and shows the square symmetry of the atomic lattice. b-Bi2Pd turns out to be a model crystalline superconductor with an excellent surface, an isotropic gap and anisotropic superconducting properties that manifest in the mixed phase.