Renormalization Effects on Quasi-Two-Dimensional Organic Conductor \alpha-(BEDT-TTF)2I3

摘要

The quasi-two-dimensional organic semiconductor \alpha-(BEDT-TTF)2I3[BEDT-TTF=bis(ethylenedithio)tetrathiafulvalene] has an anisotropic lineardispersion with a zero energy gap near the Fermi level. Owing to the vanishingdensity of states at the Fermi level, the Coulomb interaction is unscreened inthis material. We theoretically study the effect of the long-range Coulombinteraction and the low-energy/long-wavelength behavior of \alpha-(BEDT-TTF)2I3using the renormalization group analysis. The nearly logarithmic enhancement ofthe velocity reshapes tilted Dirac cones, and changes the low-temperaturebehavior. We also show the theoretical calculation for the site-selective spinsusceptibility, which can be measured in an NMR experiment.