Plasmon resonances and plasmon-induced charge transport in linear atomic chains

摘要

In linear hydrogen atomic chains, plasmon resonances and plasmon-induced charge transport are studied by time-dependent density functional theory. For the large linear chain, it is a general phenomenon that, in the longitudinal excitation, there are high-energy resonances and a large low-energy resonance. The energy of the large low-energy resonance conforms to the results calculated by the classical Drude model. In order to explain the formation mechanism of the high-energy resonances, we present a simple harmonic oscillator model. This model may reasonably account for the relationship between low-energy and high-energy resonances, and has a certain degree of universality. As the interatomic distance decreases, the current shows a gradual transition from insulator to metal. The current enhancement mainly depends on the local field enhancement associated with plasmon excitation, and the enhanced electron delocalization effect as a result of the decrease of the interatomic distance. ? 2013 Wiley Periodicals, Inc. For a large linear hydrogen chain, generally, in the longitudinal excitation, there are high-energy resonances and a large low-energy resonance. As the interatomic distance decreases, the current response shows a gradual transition from insulator to metal. The current enhancement mainly depends on the local field enhancement associated with plasmon excitation, and the enhanced electron delocalization effect as a result of the decrease of the interatomic distance.