Electron tunneling in coupled semiconductor nanostructures triggered by plasmon resonance at terahertz frequencies


Electron transport in nanostructures frequently exhibits quantum signatures, which may be advantageous for the design of novel types of nanometer-sized electronic devices. We propose to identify, observe and characterize a potentially strong quantum effect: electron tunneling between semiconductor nanoparticles over a nanometer-sized gap, induced by the plasmon resonance at THz frequencies. Unlike in metals, the period of plasmon oscillation in a semiconductor nanoparticle is much longer than the tunneling time, therefore we aim at exploration of a coupling mechanism not yet described in the literature. We will consider a prototypical system of two coupled nanoparticles and we will develop a theoretical model for its description, including energy quantization, tunneling and field enhancement close to the nanoparticle surface. Quantitative interpretation of the spectra measured using THz scattering SNOM technique with high spatial and temporal resolution will be developed to facilitate a direct comparison with the theoretical models.