Subsurface bending and reorientation of tilted vortex lattices in bulk isotropic superconductors due to Coulomb-like repulsion at the surface

We study vortex lattices (VLs) in superconducting weak-pinning platelet-like single crystals of β−Bi2Pdin tilted magnetic fields with a scanning tunneling microscope. We show that vortices exit the sample perpendicular to the surface and are thus bent beneath the surface. The structure and orientation of the tilted VLs in the bulk are, for large tilt angles, strongly affected by Coulomb-type intervortex repulsion at the surface due to stray magnetic fields. Disciplines Condensed Matter Physics | Engineering Physics | Materials Science and Engineering Authors E. Herrera, I. Guillamon, J. A. Galvis, A. Correa, A. Fente, S. Vieira, H. Suderow, A. Yu. Martynovich, and Vladimir G. Kogan This article is available at Iowa State University Digital Repository: http://lib.dr.iastate.edu/ameslab_manuscripts/32 PHYSICAL REVIEW B 96, 184502 (2017) Subsurface bending and reorientation of tilted vortex lattices in bulk isotropic superconductors due to Coulomb-like repulsion at the surface E. Herrera,1,2 I. Guillamón,1 J. A. Galvis,3,4 A. Correa,5 A. Fente,1 S. Vieira,1 H. Suderow,1 A. Yu. Martynovich,6 and V. G. Kogan6 1Laboratorio de Bajas Temperaturas y Altos Campos Magnéticos, Departamento de Física de la Materia Condensada, Unidad Asociada UAM/CSIC, Instituto de Ciencia de Materiales Nicolás Cabrera, Instituto de Física de la Materia Condensada, Universidad Autónoma de Madrid, E-28049 Madrid, Spain 2Departamento de Física, Universidad Nacional de Colombia, Bogotá 111321, Colombia 3Departamento de ciencias naturales, Facultad de ingenieria y ciencias básicas, Universidad Central, Bogotá 110311, Colombia 4National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, USA 5Instituto de Ciencia de Materiales de Madrid, Consejo Superior de Investigaciones Científicas, CSIC, E-28049 Madrid, Spain 6Ames Laboratory, Department of Physics & Astronomy, Iowa State University, Ames, Iowa 50011, USA (Received 18 March 2017; revised manuscript received 16 July 2017; published 3 November 2017) We study vortex lattices (VLs) in superconducting weak-pinning platelet-like single crystals of β-Bi2Pd in tilted magnetic fields with a scanning tunneling microscope. We show that vortices exit the sample perpendicular to the surface and are thus bent beneath the surface. The structure and orientation of the tilted VLs in the bulk are, for large tilt angles, strongly affected by Coulomb-type intervortex repulsion at the surface due to stray magnetic fields. DOI: 10.1103/PhysRevB.96.184502