King's College London

Surface plasmons are usually excited by diffraction-limited optical methods with the use of bulky optical components, which greatly limits the miniaturization and chip-scale high-density integration of plasmonic devices. By integrating a plasmonic nanostructure with a tunnel junction, plasmonic modes in the nanostructure can be directly excited by low-energy tunneling electrons with the advantages including an ultra-small footprint and an ultra-fast speed. In this mini-review, recent progress in the electric excitation of localized and propagating surface plasmons by inelastic electron tunneling is overviewed.