Vortex states in mesoscopic superconducting squares: Formation of vortex shells

Abstract

We analyze theoretically and experimentally vortex configurations in mesoscopic superconducting squares. Our theoretical approach is based on the analytical solution of the London equation using Green's-function method. The potential-energy landscape found for each vortex configuration is then used in Langevin-type molecular-dynamics simulations to obtain stable vortex configurations. Metastable states and transitions between them and the ground state are analyzed. We present our results of the first direct visualization of vortex patterns in micrometer-sized Nb squares, using the Bitter decoration technique. We show that the filling rules for vortices in squares with increasing applied magnetic field can be formulated, although in a different manner than in disks, in terms of formation of vortex "shells".

12 pages, 9 figures

References in corpus (16)

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• Matching fields of a long superconducting film

Cited by in corpus (12)

• Scanning SQUID Microscope Study of Vortex Polygons and Shells in Weak Pinning Disks of an Amorphous Superconducting Film
• Statics and Dynamics of Yukawa Cluster Crystals on Ordered Substrates
• Vortex states in nanoscale superconducting squares: the influence of quantum confinement
• Dynamics and heat diffusion of Abrikosov's vortex-antivortex pairs during an annihilation process
• Robust and tunable coreless vortices and fractional vortices in chiral $d$-wave superconductors
• SuperConga: an open-source framework for mesoscopic superconductivity
• Study of the threshold line between macroscopic and bulk behaviors for homogeneous type II superconductors
• Commensurate and Incommensurate Vortex States Confined in Mesoscopic Triangles of Weak Pinning Superconducting Thin Films
• Vortex shells in mesoscopic triangles of amorphous superconducting thin films
• Profile and Crowding of Currents in Mesoscopic Superconductors with an Array of Antidots
• Electronic structure of mesoscopic superconducting disk: Quasiparticle tunneling between the giant vortex core and disk edge
• Electron-phonon heat transfer in giant vortex states