Magnetic susceptibility of Dirac electrons in single-component molecular conductor [Pd(dddt)(2)] under pressure

摘要

Using a tight-binding model with four lattice sites per unit cell, we examine a three-dimensional Dirac electron in a single-component molecular conductor [Pd(dddt)(2)], which consists of HOMO and LUMO orbitals. The Dirac cone, which originates from the interplay of the intralayer and interlayer transfer energies, gives a semimetallic state owing to a slight variation in energy along the line of the Dirac point. Electronic states of the Dirac electron are examined by calculating the temperature (T) dependence of magnetic (spin) susceptibility. It is shown that magnetic susceptibility remains finite at zero temperature and the variation with increasing temperature exhibits a T-linear dependence. The role of the HOMO and LUMO orbitals is discussed in terms of local susceptibility. (C) 2017 The Japan Society of Applied Physics