Ab initio GW calculations for low-density carrier system

2016 Fiscal Year Final Research Report

• Project/Area Number: 25800200
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Condensed matter physics II
• Research Institution: Kyushu Institute of Technology
• Principal Investigator: Nakamura Kazuma 九州工業大学, 大学院工学研究院, 准教授 (60525236)
• Project Period (FY): 2013-04-01 – 2017-03-31
• Keywords: 第一原理計算 / 多体摂動計算 / GW計算 / 遷移金属化合物 / 有機化合物 / 低エネルギープラズモン励起 / プラズマロン状態

Outline of Final Research Achievements

We study an effect of the low-energy plasmon excitation (group electric charge excitation) on electronic structure of the material using ab initio GW calculations. We choose two benchmarks an organic compound (TMTSF)2PF6 and a transition-metal oxide SrVO3, which exhibit characteristic low-energy band structures around the Fermi level, which bring about interesting low-energy properties; the low-energy bands near the Fermi level are isolated from the other bands, and, in the isolated bands, unusually low-energy plasmon excitations occur. To study the effect of this low-energy-plasmon fluctuation on the electronic structure, we calculate spectral functions and photoemission spectra using the ab initio GW calculation. We found that the low-energy plasmon fluctuation leads to an appreciable renormalization of the low-energy bands and a transfer of the spectral weight into the incoherent part, thus resulting in an agreement with experimental photoemission data.

Free Research Field

物性理論　第一原理計算