Commensurate - Incommensurate vortex phase in a nanopatterned superconductor

Abstract

Magneto-optical imaging studies on a high-quality Bi2Sr2CaCu2O8 single crystal partially patterned with a triangular array of holes reveal enhanced flux shielding in the patterned region of the sample. By mapping local magnetic field and shielding current density distributions at different applied magnetic fields and temperatures we determine the regime where pinning from the patterned holes dominates over the intrinsic pinning in the sample. In this regime, the flux density near the center of the patterned region is observed to increase when the applied field is varied from below the matching field to just above it, while significant magnetic field gradients are sustained in the patterned region. Our measurements indicate heterogeneous pinning properties of the vortex population, exhibiting signatures of both weak and strong pinning, in the nanopatterned region of the superconductor.

arXiv comment15 pages, 7 figures

References in corpus (8)

• Elastic Theory of pinned flux lattices
• Melting of 'porous' vortex matter
• Vortex nanoliquid in high-temperature superconductors
• Vortex matching effect in engineered thin films of NbN
• High sensitivity differential Magneto-Optical Imaging with a compact Faradaymodulator
• Generating strong magnetic flux shielding regions in a single crystal of Bi2Sr2CaCu2O8 using a blind hole array
• Driven weak to strong pinning crossover in partially nanopatterned 2H-NbSe2 single crystal
• Visualizing a dilute vortex liquid to solid phase transition in a Bi2Sr2CaCu2O8 single crystal