Nonlinear optical responses in topological nodal line semimetals

Light can be rectified to a direct current by inducing real-space shifts of quasiparticles in non-centrosymmetric materials. Shifts of quasi-particles arise in all dynamical, far-from-equilibrium processes of a photo-excited material, and these shifts are fundamentally related to the nontrivial twists of electronic wavefunctions in momentum space. We study the optical response of topological nodal line semimetals protected by mirror symmetry. We show how the wavefunction geometry and topology of the materials can be linked to distinct optical signatures in nodal line semi metals, linked to their quantum geometry and how this is connected to concepts such as the Berry curvature dipole and Hopf insulators.