Dual fermion approach to Mott transition and high-energy spectroscopy of multi-orbital systems

2022 Fiscal Year Final Research Report

• Project/Area Number: 18K03541
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 13030:Magnetism, superconductivity and strongly correlated systems-related
• Research Institution: Hiroshima University
• Principal Investigator: Tanaka Arata 広島大学, 先進理工系科学研究科(先), 准教授 (70253052)
• Project Period (FY): 2018-04-01 – 2023-03-31
• Keywords: デュアルフェルミオン法 / 強相関電子系 / ハバードモデル / 金属絶縁体転移

Outline of Final Research Achievements

To discuss metal-insulator transition in two-dimensional electronic systems and electronic state of cuprate superconductors, the Hubbard model on the square lattice is investigated using the dual fermion approximation, where a newly developed Lanczos exact diagonalization method as a solver of the effective impurity Anderson model is employed. The strange metallic state, pseudo-gap state, superconducting state and phase separation in cuprate superconductors are investigated in relation with the antiferromagnetic fluctuation. Extensions of software to calculate multi-orbital systems are also conducted. In addition, the electronic states of some of transition-metal oxides such as LaCoO3 and CaCu3Ru4O12 are studied in collaboration with experimental researchers.

Free Research Field

物性理論

Academic Significance and Societal Importance of the Research Achievements

新たに開発したLanczos厳密対角化法を用いたデュアルフェルミオン法を用いることで、強相関電子系で一般的に用いられている量子モンテカルロでは困難な低温での電子状態の精密な計算できるようになり、強相関電子系の理論の進展が期待できる。また、将来的には、これらの物質の電子状態の理解が進むことで、新しい機能性材料の開発が可能になると期待できる。