Ultrafast near-field dynamics of polariton-exciton in WSe2slab waveguides at room temperature

摘要

We observe the propagation of an exciton-polariton wave in a WSe2 nanometric slab. We directly visualize with unprecedented spatio-temporal resolution (50 nm, <70 fs) a strikingly slow polaritonic wave with a velocity of ∼ 0.017c.