Critical Current Density in d-Wave Hubbard Superconductors

Area of Science:

• Condensed Matter Physics
• Materials Science

Background:

• High critical temperature superconductors are crucial for advanced technologies.
• Understanding their electrical properties, particularly critical current density (Jc), is essential for practical applications.

Purpose of the Study:

• To evaluate the electrical current density of high critical temperature d-wave superconductors using the Generalized Hubbard Model.
• To establish a maximum limit for the critical current density achievable by d-wave superconductors.

Main Methods:

• Application of the Generalized Hubbard Model on a square lattice.
• Hamiltonian parameter tuning to match experimental critical temperatures (Tc) near 100 K.
• Analysis of quasiparticle dispersion relation E(k) and its gradient to determine electron velocity.

Main Results:

• The model achieved a good quantitative fit with macroscopic superconducting properties like Tc and Jc.
• A d-wave symmetry in pairing interaction was found to influence Jc.
• Maximum Jc values were calculated: ~1.41×10^8 A/cm^2 near the antinodal direction and ~2.21×10^9 A/cm^2 along the nodal direction.

Conclusions:

• The Generalized Hubbard Model provides an effective framework for studying d-wave superconductors.
• The study establishes directional dependencies and maximum limits for critical current density in these materials.
• Findings contribute to the understanding and potential application of high-Tc d-wave superconductors.