Quantum Plasmonics in Sub-Atom-Thick Optical Slots.

ABSTRACT: We show using time-dependent density functional theory (TDDFT) that light can be confined into slot waveguide modes residing between individual atomic layers of coinage metals, such as gold. As the top atomic monolayer lifts a few Å off the underlying bulk Au (111), ab initio electronic structure calculations show that for gaps >1.5 Å, visible light squeezes inside the empty slot underneath, giving optical field distributions 2 Å thick, less than the atomic diameter. Paradoxically classical electromagnetic models are also able to reproduce the resulting dispersion for these subatomic slot modes, where light reaches in-plane wavevectors ∼2 nm^-1 and slows to <10^-2c. We explain the success of these classical dispersion models for gaps ≥1.5 Å due to a quantum-well

SUBMITTER: Baumberg JJ 

PROVIDER: S-EPMC10722603 | biostudies-literature | 2023 Nov

REPOSITORIES: biostudies-literature