Collaboration between researchers from IMDEA Nanoscience and IFIMAC-UAM demonstrating that plasmonic picocavities, with mode volumes of less than 1 nm cubic, can act as directional antennas. In particular, the work focuses on the nanocavity formed between the tip of a scanning tunneling microscope and a metal surface with a monoatomic step, demonstrating its directional emission profile. Electromagnetic calculations show that the observed directionality arises from the remodelling and tilting of the surface charges induced at the scanning tip due to the atomic step. Our results pave the way for exploiting picoantennas as an effective means for far-field probing and monitoring light-matter interactions below the nanoscale. [Full article]
