Quantum theory of rare-earth magnets

The Korringa–Kohn–Rostoker method combined with the coherent potential approximation(KKR–CPA) is a powerful tool for calculating single-particle properties of disordered alloys.This technique is extended so as to calculate transport properties of disordered systems[1][2]. The formalism is based on the Kubo–Greenwood formula at T=0. In its proto-type, theeffects of electron–phonon and electron–magnon scatterings are not taken into account. Themain objective of the present study is to develop a practical first principles scheme that cancalculate the conductivity as well as the Seebeck coefficient of metallic systems at finitetemperature including the effects of electron–phonon and electron–magnon scattering. Ourapproach combines 1) linear response theory in the framework of the KKR method, 2) localphonon and magnon approach, and 3) alloy analogy model [3]. As an example, the results ofthe calculation on pure bcc Fe are shown below. The calculations employ the AKAI-KKR andQUENTUM-ESPRESSO codes. The calculated resistivity and the Seebeck coefficient forvarious systems at finite temperature are discuss                              References[1] W. H. Butler, Phys. Rev. B 31, 3260 (1985).[2] M. Oshita, S. Yotsuhashi, H. Adachi, and H. Akai, J. Phys. Soc. Jpn. 78, 024708(2009).[3] H. Ebert, S. Mankovsky, et al., Phys. Rev. B 91, 165132 (2015).

ESICMM, MI2I, CDMSI, 科研費2600330, 17K05556