Nonuniform and coherent motion of superconducting vortices in the picometer-per-second regime

Abstract

We investigated vortex dynamics in a single-crystal sample of type-II superconductor NbSe${}_2$ using scanning tunneling microscopy at 4.2 K. The decay of the magnetic field at a few nT/s in our superconducting magnet induced the corresponding motion of vortices at a few pm/s. Starting with an initial magnetic field of 0.5 T, we continued to observe motion of vortices within a field of view of 400$\times$400 nm${}^2$ subject to decay of the magnetic field over a week. Vortices moved collectively, and maintained triangular lattices due to strong vortex-vortex interactions during the motion. However, we observed two peculiar characteristics of vortex dynamics in this superconductor. First, the speed and direction of the vortex lattice motion were not uniform in time. Second, despite the non-uniform motion, we also found that there exists an energetically favored configuration of the moving vortices in the single-crystal sample of NbSe${}_2$ based on the overlaid trajectories and their suppressed speeds. We model the system with weak bulk pinning, strong bulk pinning, and edge barrier effects.

6 pages, 4 figures, Physical Review B (R) in press (2011)

References in corpus (4)

• Direct observation of melting in a 2-D superconducting vortex lattice
• Dynamics of single vortices in grain boundaries: I-V characteristics on the femto-volt scale
• Single vortices observed as they enter NbSe${}_2$
• Unzipping Vortices in Type-II Superconductors

Cited by in corpus (6)

• Imaging of super-fast dynamics and flow instabilities of superconducting vortices
• Imaging superconducting vortex core and lattice with the scanning tunneling microscope
• Probing dynamics and pinning of single vortices in superconductors at nanometer scales
• Controlled Ordering of Room-Temperature Magnetic Skyrmions in a Polar Van der Waals Magnet
• Vortex creep at very low temperatures in single crystals of the extreme type-II superconductor Rh${}_9$In${}_4$S${}_4$
• Sliding elastic lattice: an explanation of the motion of superconducting vortices