Quantum transportation in terms of local physical quantities defined in quantum field theory

2022 Fiscal Year Final Research Report

• Project/Area Number: 17K04982
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Nanostructural physics
• Research Institution: Kyoto University
• Principal Investigator: Senami Masato 京都大学, 工学研究科, 講師 (40431770)
• Project Period (FY): 2017-04-01 – 2023-03-31
• Keywords: 量子電気伝導 / スピン渦 / 局所コンダクタンス

Outline of Final Research Achievements

Quantum transportation had been discussed in quantum mechanics. In this work, it has studied in quantum field theory, which is an advanced theory over quantum mechanics. Particularly, local physical quantities, local conductance and spin vorticity density, defined in quantum field theory is used to analyze.
It has been shown that local conductance is consistent with the conductance of the Landauer formula by using models (benzenedithiol and graphene).
The linear relation between the spin vorticity density and electric current density is proposed and this relation has been confirmed in numerical computations for some models, such as helicene and graphene.

Free Research Field

量子理論

Academic Significance and Societal Importance of the Research Achievements

本研究の局所量を用いた解析手法では、分子内の特定の官能基、特定の原子の効果や、固体内の特定の空孔や不純物がナノ材料全体の物性値へと与える効果を定量的に珪砂することができる。これまではAという分子と一部の官能基を異なる官能基に置換したA'という分子を計算して物性値の違いから比較して間接的にその効果をみるということしかできなかったが、材料のどの部分がどのような効果を持つのか定量的に調べられる道具立てを手に入れたことになる。