Nonperturbative quantum effects in Dirac materials

2016 Fiscal Year Final Research Report

• Project/Area Number: 15H06023
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Single-year Grants
• Research Field: Condensed matter physics II
• Research Institution: Tohoku University
• Principal Investigator: Araki Yasufumi 東北大学, 学際科学フロンティア研究所, 助教 (10757131)
• Co-Investigator(Renkei-kenkyūsha): NOMURA Kentaro 東北大学, 金属材料研究所, 准教授 (00455776)
• Research Collaborator: YOSHIDA Akihide
• Project Period (FY): 2015-08-28 – 2017-03-31
• Keywords: 物性理論 / 強相関電子系 / スピンエレクトロニクス / 半導体物性 / トポロジカル物質 / ディラック電子 / 磁壁

Outline of Final Research Achievements

The goal of this project was to understand the interaction effects on electrons in "Dirac materials" including topological insulators and Dirac-Weyl semimetals, from the point of view of quantum field theory. I found the following three points: (1) The Coulomb interaction between electrons turns the system into an insulator, and renormalizes the electron Fermi velocity. (2) The exchange interaction between electron spins and local spins leads to a nontrivial effective exchange interaction between the local spins. (3) A magnetic domain wall formed in Weyl semimetals hosts a finite localized charge, and its motion can be driven by an external electric field.

Free Research Field

物性物理学（理論）