In the search for efficient building blocks nonlinear metamaterials, plasmonic nanoparticles have received considerable attention. Their quadratic optical properties result from a complex interplay between nature of bulk material, object shape, surface defects, and retardation effects. This versatility can be used to tailor resulting material. However, despite extensive investigation, separatin...

We study electric-field-induced second harmonic generation (SHG) in the Kitaev model. This frustrated magnet hosts a quantum spin liquid, featuring fractionalization terms of mobile Majorana fermion and static ${\mathbb{Z}}_{2}$ flux-vison elementary excitations. show that finite-temperature SHG allows to probe characteristic features both fractional quasiparticle types. In homogeneous flux sta...

We demonstrate energy exchange between two orthogonally polarized optical waves as a consequence of a two-color multistep parametric interaction. The energy exchange results from cascading of two quasi-phase-matched (QPM) second-harmonic parametric processes, and it is intrinsically instantaneous. The effect is observed when both the type-I (ooe) second-harmonic generation process and higher QP...