Atomic structure and electronic properties of adsorbate-substrate interface systems

Research Aim

To create a new functional element that operates at a practical level by arranging the organic molecules on the surface of the substrate, it is necessary to understand the electronic state of the surface at the atomic level. The purpose of this study is to investigate by theoretical calculations a response to: the stable atomic structure in molecule system built on a surface; the electronic and spin properties in thermal equilibrium; and external fields such as optical and electric fields.

Role and Need in the Group

Together with the experimental groups in this area, we will conduct a theoretical analysis in line with the most advanced experimental results in the area, such as single-molecule magnets, two-dimensional components under a strong magnetic field, and surface electrical conductivity. We will also work with the theory groups in this area on difficult problems such as a theory of conduction under a finite bias voltage that considers the strong electron correlation effect.

Research Content

(1) Elucidation of the stable atomic structure of the interface: Injection efficiency of electron and spin to the molecular structure is sensitive to many things including adsorption sites, therefore determination of a stable interfacial atomic structure is important. We will clarify the first-principles DFT calculation program and the stable atomic arrangement of adsorption surfaces. (2) Detailed elucidation of the one-electron state: We will conduct semi-infinite system DFT calculations using the embedded Green method and examine in detail the electronic state of surfaces. We will calculate the tunnel current for the electrode–molecule–electrode system and consider the injection efficiency of electronic and spin current. (3) Elucidation of strong correlation effects and dynamic response to external fields: We will examine physical phenomena, such as the Kondo effect, derived from quantum many-body calculation and quantum chemical calculations by using a model Hamiltonian that captures the essence of a system. We will also elucidate the non-linear response to light and electronic fields of the adsorbed molecules through the simultaneous integration of the Maxwell-Schrödinger equation.

Others

Members

Research representative: Hiroshi Ishida Professor / Nihon University College of Humanities and Sciences

Member of the research project: Tokuei Sako Associate Professor / Nihon University College of Science and Technology

Researchers coordinated with: Yoshitada Morikawa Professor / Osaka University Graduate School of Engineering

Member of the research project: Yuji Hamamoto Assistant Professor / Osaka University Graduate School of Engineering