Time Resolved Stroboscopic Neutron Scattering of Vortex Lattice Dynamics in Superconducting Niobium

TL;DR

This study uses time-resolved neutron scattering to directly measure vortex lattice dynamics in ultra-pure niobium, revealing temperature-dependent behavior and surface domain effects, advancing understanding of vortex matter in superconductors.

Contribution

First direct microscopic measurement of vortex lattice tilt modulus c44 in niobium using time-resolved small angle neutron scattering, highlighting vortex dynamics and surface effects.

Findings

Faster vortex lattice dynamics with increasing temperature

Observation of a changeover in relaxation process linked to vortex morphology

Identification of Landau-branching of Shubnikov domains at the surface

Abstract

Superconducting vortex lattices, glasses and liquids attract great interest as model systems of crystallization and as a source of microscopic information of the nature of superconductivity. We report for the first time direct microscopic measurements of the vortex lattice tilt modulus c44 in ultra-pure niobium using time-resolved small angle neutron scattering. Besides a general trend to faster vortex lattice dynamics for increasing temperatures we observe a dramatic changeover of the relaxation process associated with the non-trivial vortex lattice morphology in the intermediate mixed state. This changeover is attributed to a Landau-branching of the Shubnikov domains at the surface of the sample. Our study represents a showcase for how to access directly vortex lattice melting and the formation of vortex matter states for other systems.