Electronic structure of the organic superconductor κ-(BEDT-TTF)2Cu(NCS)2[where BEDT-TTF is bis(ethylenedithio)tetrathiafulvalene] studied by scanning tunneling microscopy

Abstract

The bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF) molecules in κ-(BEDT-TTF${)}_2$Cu(NCS${)}_2$ crystals were observed directly by scanning tunneling microscopy. Carrier distribution observed on the BEDT-TTF molecules were in good agreement with the electronic structure calculated by an ab initio method based on the dimerized molecular structure determined by x-ray diffraction. The layer structure consisting of a stack of alternate conductive and insulating layers was clearly observed.