Vortex lattice structural transitions: a Ginzburg-Landau model approach

Area of Science:

• Condensed Matter Physics
• Materials Science

Background:

• Anisotropic superconductors exhibit complex vortex lattice structures.
• Understanding phase transitions is crucial for superconductor applications.

Purpose of the Study:

• Analyze the rhombic to square vortex lattice phase transition in anisotropic superconductors.
• Investigate the influence of anisotropy and thermal fluctuations on vortex lattice structure.

Main Methods:

• Utilized a variant of Ginzburg-Landau theory.
• Determined the mean-field phase diagram to second order in the anisotropy parameter.
• Derived long-wavelength elastic moduli of the lattices.

Main Results:

• Identified a reorientation transition of the square vortex lattice relative to the crystal lattice.
• Demonstrated that thermal fluctuations induce a reentrant rhombic to square lattice transition line.

Conclusions:

• The study provides a theoretical framework for understanding vortex lattice transitions in anisotropic superconductors.
• Findings align with recent experimental and theoretical models, highlighting the role of thermal fluctuations.