Chain molecules: Geometric and electronic structures
Young Kuk
Department of Physics, Seoul National University, Seoul, 151-742, Korea
Electric address: ykuk@phya.snu.ac.kr
Chain molecules have drawn much attention to scientific community for their application to interconnetion wires, functional devices, energy harvesting materials. Various long chain molecules have been studied with scanning tunneling microscopes, scanning gate microscopes and conventional transport measurements. Many new physics can be learned from the studies on these one dimensional systems, such as 1) deviation from Fermi liquid, 2) different defect bands from the 3-D counter parts, 3) fluctuation in metallic or superconducting wires, 4) energy transfer mechanisms.
Experimentally, carbon nanotubes, azobenzene and pentacene molecules were placed on top of clean single crystal metals or insulating layers on metal substrates. The geometrical and electronic structures were studied with STM. Several new results will be presented in this talk. In some wires, scanning tunneling spectroscopy showed additional standing waves, suggesting spin and charge separation in 1-D. Defect bands are quite different from those in 1D, and they may work as new scattering centers.