Controlling Nanoscale Heat With Optically Coupled Plasmonic Systems.

The management of thermal effects in plasmonic nanostructures is frequently viewed as a detrimental byproduct rather than a useful controllable entity. Through numerical investigation of experimentally achievable systems, it is demonstrated how plasmon hybridization and near-field coupling dictate the magnitude and spatial distribution of temperature, enabling precise spatiotemporal control over nanoscale heating. The results highlight the critical role of polarization and gap distance in tuning the thermal output of dimers, the ability of a trimer nanolens to focus heat into a sub-diffraction volume reducing required laser intensities by an order of magnitude, and pronounced thermal differences in a switchable nanoparticle cluster. This work provides design principles for advanced thermoplasmonic systems where heat is not merely a detriment, but a dynamically controllable element for applications in catalysis, health, or active photonic devices.