Jahrestagung der Österreichischen Physikalischen Gesellschaft 2021
Sprache des Tagungstitel:
Nonlinear nanoscale optics, a success story driven by ultra-short laser pulses of immense power, commonly invokes surface plasmons, highly sensitive to details of thet ightly confined electric field. Intrinsically 2D materials like graphene or so-called TMDs additionally offer gate-tunability of their nonlinear response. We develop the spectral representation of nth order response functions in general, then focus on the cubic longitudinal density response of charge carriers in semiconductor hetero-structures. Depending on the perturbing signal, collective and single-particle modes give a rich spectrum displaying multifaceted frequency mixing. We further discuss spin-/valley-polarized systems, relevant in plasmonics, and give preliminary results for graphene.