Abstract
We have investigated the electron transport in single--molecule transistors under the illumination of intense monochromatic terahertz (THz) radiation. By employing an antenna structure with a sub-nm-wide gap, we concentrate THz radiation beyond the diffraction limit and focus it onto a single molecule. Photon-assisted tunneling (PAT) in the single molecule transistors is observed in both the weak-coupling and Kondo regimes. The THz power dependence of the PAT conductance indicates that when the incident THz intensity is a few tens of mW, the THz field induced at the molecule exceeds , which is enhanced by a factor of from the field in the free space.
- Received 6 March 2015
DOI:https://doi.org/10.1103/PhysRevLett.115.138302
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