Controlling the interaction of light with nanomaterials: from twisted multilayers to plasmonic nanoparticles

Nanoscale materials exhibit fascinating light-matter interactions: in twisted multilayers, bound electron-hole pairs called excitons are trapped by the moiré superlattice potential and in metallic nanoparticles collective charge density oscillations called localized surface plasmons give rise to enormous light absorption cross-sections which can be harnessed in optoelectronic devices. In my talk, I will describe how these phenomena can be understood and controlled using atomistic quantum-mechanical modelling approaches. First, I will describe the optical signatures of charged defects in two-dimensional semiconductors. Then, I will discuss quadrupolar excitons in twisted trilayer materials. Finally, the generation of highly energetic electrons and holes (also known as hot carriers) from the decay of localized surface plasmons in metallic nanoparticles will be analyzed.

Speaker: Jhannes Lischner, Imperial College, London