First-Principles Study of Electronic Structure in α-(BEDT-TTF)₂I₃at Ambient Pressure and with Uniaxial Strain

Abstract

Within the framework of the density functional theory, we calculate the\nelectronic structure of $\\alpha$-(BEDT-TTF)$_2$I$_3$ at 8K and room temperature\nat ambient pressure and with uniaxial strain along the $a$- and $b$-axes. We\nconfirm the existence of anisotropic Dirac cone dispersion near the chemical\npotential. We also extract the orthogonal tight-binding parameters to analyze\nphysical properties. An investigation of the electronic structure near the\nchemical potential clarifies that effects of uniaxial strain along the a-axis\nis different from that along the b-axis. The carrier densities show $T^2$\ndependence at low temperatures, which may explain the experimental findings not\nonly qualitatively but also quantitatively.\n