Abstract
In this paper, we derive the optical response of nanowire dimers with subnanometer gap sizes using different models, viz., the classical, quantum-corrected, nonlocal, and quantum-corrected nonlocal models. Our results indicate that both the quantum tunneling and the nonlocal response should be considered for the gap sizes less than 0.5 nm. We find that, when the quantum tunneling cannot be neglected, the nonlocal response is crucial in explaining the field enhancement at higher frequencies instead of the field collapse phenomenon if the nonlocal effect is ignored. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4769348]