抄録
Among various lattices, the Kagomé lattice is special because it has a completely flat electronic band whose eigenstates have both localized and itinerant characters. We investigate electron transport properties of finite-size Kagomé-lattice-chain systems, which have multi-degenerate flat-band-like states, using a simple tight-binding model and a nonequilibrium Green function method. It is found that the flat-band-like-state channel in a Kagomé-lattice-chain system generates a large electronic current along the chain when a small electric field is applied perpendicular to the chain, while no current is generated along the chain when an electric field is applied along the chain. We show that such unique transport characteristics originate from the symmetry breaking of flat-band-like states by the external electric fields. [DOI: 10.1380/ejssnt.2005.399]
