Universal slow plasmons and giant field enhancement in atomically thin quasi-two-dimensional metals

Abstract

Plasmons depend strongly on dimensionality. Here the authors show that plasmons in atomically thin metals are qualitatively different from those in a 2D electron gas or metal slab: they are dispersionless at large wavevectors and, in systems such as monolayer TaS2, long-lived enough to be observed experimentally as localized plasmon wave packets.