Bond-electromagnetic origin of superconducting pairing across materials

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Mechanics

Background:

• Superconductivity is a quantum mechanical phenomenon where electrical resistance vanishes.
• Understanding the microscopic origins of superconductivity, particularly the pairing mechanism, remains a key challenge.
• Existing theories often focus on electron-phonon interactions or electronic correlations, with less emphasis on dynamic structural contributions.

Purpose of the Study:

• To establish a novel theoretical framework linking dynamic covalent bonds to superconducting pairing.
• To develop a method for predicting superconducting properties using experimentally accessible structural parameters.
• To demonstrate the framework's applicability across different material classes and superconducting regimes.

Main Methods:

• Development of a bond-electromagnetic framework incorporating dynamic covalent bonds and their fluctuations.
• Formulation of a real-space pairing kernel derived from structural fluctuations.
• Structural reformulation of the Allen-Dynes expression to determine the microscopic pairing scale.
• Analysis of London kernel and superfluid stiffness to quantify long-range superconductivity.

Main Results:

• The framework successfully reproduces pairing scales for elemental Al and Pb using only structural inputs.
• A structurally constrained formula accurately models the pressure-induced superconducting dome in FeSe.
• The model demonstrates that bond dynamics provide a direct link between lattice structure, electromagnetic response, and superconducting coherence.

Conclusions:

• Superconducting pairing is fundamentally anchored in the dynamic covalent bonds of a material.
• The bond-electromagnetic framework offers a practical, materials-level approach to understanding and predicting superconductivity.
• Experimentally accessible structural quantities serve as crucial predictors of superconducting behavior.