Nonlocal Effects in Plasmons of Grooved Gold Cylindrical Structures Based on Modified Hydrodynamic Theory

This work explores the nonlocal behavior of the optical response of infinitely long gold (Au) cylindrical nanostructures (ILANs) with controllable grooves. By varying three parameters, such as the number of grooves, the groove width, and the material of the connector, the systematic calculations of the plasmon resonance peaks of ILANs are performed under classical local theory and modified hydrodynamic (nonlocal) theory. We find that the properties of metallic nanostructures calculated using local theory are not significantly dependent on changes in their size, shape, or environment. However, under nonlocal theory, we observe that the optical properties of ILANs is highly reliant on these three variables. Compare to the classical local theory, we successfully apply the more accurate modified hydrodynamic theory to complex nanometallic structures, which lays a foundation for the theory and design of optical devices.