Seminarium Fizyki Materii Skondensowanej

One of the primary goals of plasmonics is to confine light at subwavelength scales. This aim is motivated by the desire to both transport and manipulate light over macroscopic distances. Here we investigate collective plasmonic modes in chains of spherical metallic nanoparticles, which are coupled by near-field interactions. Using an open quantum system approach in which the collective plasmons are interacting with vacuum electromagnetic modes, we analytically evaluate the resulting radiative frequency shifts of the plasmonic bandstructure. This is a remarkable manifestation of the collective Lamb shift in a nanoplasmonics setting. We go on to consider a dimerization of the nanoparticle chain, which leads to the emergence of topological plasmonic edge states, as codified by a nontrivial Zak phase. These exotic edge states are found to be robust against long-range quasistatic interactions, bosonic statistics, retardation effects and non-resonant coupling terms.