Fig. 3: Electrical conductivity of SiO₂ from numerical simulations.

a Real (thick curves) and imaginary (thin curves) parts of the electrical conductivity of silica as a function of the excitation energy according to the numerical simulations. The solid curves are related to stishovite Hugoniot states; the dashed-dotted curves are related to stishovite off-Hugoniot states. The dark and light grey vertical lines identify the excitation energies corresponding to the probe-laser frequencies ω_L and 2ω_L, respectively. The yellow dots represent the real and imaginary conductivity values as deduced from the reflectivity measurements at the two probe energies for shot A40 at a temperature of (16.2 ± 3.2) × 10³ K (detailed values are reported in Supplementary Table II). b Ratio between the static conductivity and the real part of the conductivity at 532 nm (\(\sigma (0)/\Re [\tilde{\sigma }(2{\omega }_{\text{L}})]\)) according to calculations from Laudernet et al.¹⁷ and this work, as a function of temperature. c Opposite of the ratio between the imaginary and real parts of the conductivity at 532 nm (\(-\Im [\tilde{\sigma }(2{\omega }_{\text{L}})]/\Re [\tilde{\sigma }(2{\omega }_{\text{L}})]\)) according to calculations from Laudernet et al.¹⁷ and this work, as a function of temperature. The fit curves are defined in the Methods section and in the Supplementary Notes 5.