Tuning nonlocal effects in grooved cylindrical plasmons by hydrodynamic model: A competing mechanism

Using the linearized hydrodynamic equations, we explore the optical characteristics of grooved cylinders of different groove numbers and widths, which have a strong impact on the corresponding resonance peaks. The number of grooves is an important new variable parameter to tune the energy of the dipolar plasmon without appreciable broadening of the plasmonic peak. As the groove number and width increase, the excitation and interesting anomalous redshifts of plasmonic higher-order modes are found, which can be unraveled by a competing mechanism between nonlocal effects and surface electron scattering. These findings are of importance for further apprehending the optical belongings of nanoscale complex structures and play a significant guiding role in the design of tunable plasmonic devices.