Diffractive dipolar coupling in non-Bravais plasmonic lattices. Issue 3 (26th February 2020)

• Record Type: Journal Article
• Authors: Becerril, David; Vázquez, Omar; Piccotti, Diego; Sandoval, Elizabeth Mendoza; Cesca, Tiziana; Mattei, Giovanni; Noguez, Cecilia; Pirruccio, Giuseppe
• Is Part Of: Nanoscale advances. Volume 2:Issue 3(2020)
• Page Start: 1261
• Page End: 1268
• Publication Date: 2020-02-26
• Subjects: 620.5
• DOI: 10.1039/d0na00095g
• Languages: English
• ISSNs: 2516-0230

Abstract

Abstract : Honeycomb plasmonic lattices are characterized by a 2-particle unit cell. The difference between the intrasublattice and intersublattice coupling is distinctive of non-Bravais lattices. Although the two particles are identical the two types of coupling may be different. Abstract : Honeycomb plasmonic lattices are paradigmatic examples of non-Bravais lattices. We experimentally measure surface lattice resonances in effectively free-standing honeycomb lattices composed of silver nanospheres. By combining numerical simulations with analytical methods, we analyze the dispersion relation and the near-field properties of these modes along high symmetry trajectories. We find that our results can be interpreted in terms of dipole-only interactions between the two non-equivalent triangular sublattices, which naturally lead to an asymmetric near-field distribution around the nanospheres. We generalize the interaction between the two sublattices to the case of variable adjacent interparticle distance within the unit cell, highlighting symmetry changes and diffraction degeneracy lifting associated to the transition between Bravais and non-Bravais lattices.