Viscoelasticity and Surface Tension at the Defect-Induced First-Order Melting Transition of a Vortex Lattice

TL;DR

This paper demonstrates how defects induce first-order melting in vortex lattices, aligning well with experimental data, and explores the viscoelastic properties and surface tension effects at the transition.

Contribution

It introduces a defect-based model explaining vortex lattice melting and characterizes the viscoelastic and surface tension properties at the transition.

Findings

Good agreement with experimental melting curves, latent heat, and magnetization jumps.

Frequency-dependent shear modulus of the vortex liquid.

Presence of a small surface tension between vortex line liquid and lattice.

Abstract

We show that thermally activated interstitial and vacancy defects can lead to first order melting of a vortex lattice. We obtain good agreement with experimentally measured melting curve, latent heat, and magnetization jumps for YBCO and BSCCO. The shear modulus of the vortex liquid is frequency dependent and crosses over from zero at low frequencies to a finite value at high frequencies. We also find a small surface tension between the vortex line liquid and the vortex lattice.