When traditional materials—such as noble metals—with a well-understood optical response are explored at the atomistic level, unconventional electrodynamics due to nonlocal, surface or quantum effects might emerge. Identifying, quantifying, and understanding this complex optical response is vital for applications in communications and sensing. At the same time, achieving such a detailed description of a material is experimentally challenging because of possible sample contamination and surface roughness, while theoretical approaches rapidly become computationally impractical.
Surface-response functions promise to provide an efficient bridge between large-scale electrodynamics and atomistic descriptions. While analytical and numerical methods for their theoretical determination already exist, their successful implementation into everyday nanophotonics relies on the ability to experimentally verify the theoretical predictions, and clearly distinguish between quantum effects and fabrication imperfections.
Polaritons in 2D materials, deposited on or encapsulating a sample such as a noble-metal flake, act as sensitive probes for the electrodynamics dominating the sample. Plasmons in graphene, phonon polaritons in hBN, and image polaritons in van der Waals heterostructures, sensitively depend on their surroundings, allowing one to explore and characterize the surface-response functions of the sample, together with other unconventional states such as the Shockley/Tamm surface states in metals and artificial periodic media, or the Higgs mode in superconductors.
Surface-response functions promise to provide an efficient bridge between large-scale electrodynamics and atomistic descriptions. While analytical and numerical methods for their theoretical determination already exist, their successful implementation into everyday nanophotonics relies on the ability to experimentally verify the theoretical predictions, and clearly distinguish between quantum effects and fabrication imperfections.
Polaritons in 2D materials, deposited on or encapsulating a sample such as a noble-metal flake, act as sensitive probes for the electrodynamics dominating the sample. Plasmons in graphene, phonon polaritons in hBN, and image polaritons in van der Waals heterostructures, sensitively depend on their surroundings, allowing one to explore and characterize the surface-response functions of the sample, together with other unconventional states such as the Shockley/Tamm surface states in metals and artificial periodic media, or the Higgs mode in superconductors.