Motivated by the sensitivity of ${\mathrm{Sr}}_2{\mathrm{RuO}}_4$ to Fermi surface reconstructions under strain, we investigate how Fermi surface geometry and Van Hove singularities influence the optical Hall response and polar Kerr effect. Within a three-orbital model, we explore the impact of chemical potential and interlayer hopping on superconducting pairing and response functions. We find that $d_{x^2-y^2}$ and $d_{x^2-y^2}+ig$ symmetries are the leading candidates for the quasi-two-dimensional (quasi-2D) orbital, while a chiral $p$-wave state in quasi-1D orbitals is essential for generating an accessible Kerr angle. The Lifshitz transition is shown to affect coherence factors and density-of-states peaks, producing sharp signatures in $T_c$ and optical transport. Interorbital charge transfer further enhances these effects by modifying the balance between the contributions of the quasi-1D and quasi-2D orbitals. These results provide a framework for interpreting Kerr effect experiments in multiorbital superconductors.

Close

PrevNext

View figure in article

• Magneto-optical Kerr effect
• Multiband superconductivity
• Spin-orbit coupling
• Spin-singlet pairing
• Spin-triplet pairing
• Superconducting gap
• Superconducting order parameter
• Superconductivity
• High-temperature superconductors
• Ruthenates