Dirac fermions and Kondo effect

International Workshop on Dirac Electrons in Solids 2015

Yanagisawa, Takashi^1

Electronics and Photonics Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 2, 1-1-1 Umezono, Tsukuba

305-8568, Japan^1

关键词: Dirac fermions;    Kondo temperatures;    Linear dispersion;    Localized spin;    Pauli matrices;    Unit matrix;    Wave numbers;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/603/1/012014/pdf
DOI  :  10.1088/1742-6596/603/1/012014

来源: IOP

【 摘 要 】

In this study, we investigate the Kondo effect induced by the s-d interaction where the conduction bands are occupied by Dirac fermions. The Dirac fermion has the linear dispersion and is described typically by the Hamiltonian such as Hk= νk•σ + mσ0for the wave number k where σjare Pauli matrices and σ0is the unit matrix. We derived the formula of the Kondo temperature TKby means of the Green's function theory for Green's functions including Dirac fermions and the localized spin. The TKwas determined from a singularity of Green's functions in the form TK∝ exp( - const/ρ|J|). The Kondo effect will disappear when the Fermi surface is point like.