Bose-Einstein condensates of exciton-polaritons: their formation, coherence, statistical and dynamic properties (superfluidity, topological defects), with an applied goal, the manufacture of polariton lasers, interferometers, parametric oscillators, optical transistors, and other non-linear optical components, including for communications and quantum computing.
Topological systems (topological insulators, chains of dimers) and the associated effects (chiral edge states, spin currents).
Analog physics: the emulation of inaccessible systems and effects (magnetic monopoles, Klein tunnelling effect, formation of topological defects after the Big Bang).