Fig. 5: Magneto-optic Kerr effects in fully gapped chiral superconductors.

a−c Two-band model of superconductivity from a chiral metal with Δ_y = 10 meV. ∣M∣ = 20 meV, \(\hslash v/{a}_{\parallel }=A/{a}_{\parallel }^{2}=0.5\) eV, and Γ = 1 meV. To regularize the UV divergence in calculating the superfluid weight using Eq. (14), we calculate it with reference to μ = 0. Namely, we replace D^xx with D^xx − D^xx(μ = 0). In (a, b) E_F = 20 meV. In (c) the lower plasmon frequency is calculated and compared with approximated expressions. The exact value is obtained by numerically solving \({{\rm{Re}}}[{n}_{\pm }^{2}({\omega }_{\pm })]=0\). Equation (2) is very close to the exact value. The approximation ω_p,lower ≈ D/σ_H(0) becomes more accurate when σ_H is larger. d-e Electron-doped FeSe model with chiral superconducting pairing Δ₀ = 10 meV. Γ = 0.1 meV. The reflectances and Kerr angles are calculated for the normal incidence on bulk crystals. We take the interlayer lattice constant a_z = 5 Å for all calculations.