Theory of Spin and Charge Distributions Controlled by Quantum Dot Systems with Geometric Structure

2015 Fiscal Year Final Research Report

• Project/Area Number: 25400322
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Condensed matter physics I
• Research Institution: Shizuoka University
• Principal Investigator: KOGA Mikito 静岡大学, 教育学部, 教授 (40324321)
• Co-Investigator(Kenkyū-buntansha): MATSUMOTO Masashige 静岡大学, 理学部, 教授 (20281058) ; KUSUNOSE Hiroaki 明治大学, 理工学部, 准教授 (00292201)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 量子ドット / 近藤効果 / スピン電荷制御 / 誘起電気分極 / マルチフェロイックス / アハラノフ・ボーム効果

Outline of Final Research Achievements

We studied the controllability of spin and charge distributions through a quantum effect called "Kondo effect", using a triangular triple-quantum-dot system in which each quantum dot is regarded as an artificial atom. In the field of nanotechnology, we introduce a new aspect of multiferroics, for instance, a magnetic-field control of electric polarization.
The main results are as follows: (1) a sign reversal of emergent electric polarization through a competition between two quantum states; (2) field control of oscillation patterns of emergent electric polarization; (3)a sign reversal of emergent electric polarization through the Kondo effect due to molecular orbitals of the triangular loop.
The above results would contribute to opening up a new area of the Kondo physics.

Free Research Field

物性理論