Current fluctuation by non-equilibrium Kondo effect in quantum dot

2015 Fiscal Year Final Research Report

• Project/Area Number: 25800174
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Condensed matter physics I
• Research Institution: The University of Tokyo
• Principal Investigator: Sakano Rui 東京大学, 物性研究所, 助教 (00625022)
• Research Collaborator: Oguri Akira 大阪市立大学, 大学院理学研究科, 教授 (10204166) ; Kobayashi Kensuke 大阪大学, 大学院理学研究科, 教授 (10302803)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 量子ドット / 多体効果 / 電流揺らぎ

Outline of Final Research Achievements

We have studied that dynamic properties of non-equilibrium steady states of the Kondo effect which is a typical quantum many-body effect formed in quantum dot, and non-equilibrium current fluctuations induced by them. It is succeeded to experimentally observe shot noise and effective charge state of the Kondo state in a carbon-nanotube quantum dot with high accuracy in collaboration with an experimental group. The exact solution of the impurity Anderson model which describe quantum dot systems, is derived at the high bias-voltage or high temperature limits, and many-body effects at the high energy limit is elucidated. Furthermore, it is elucidated that, entanglement properties of the quasiparticle pairs forming in non-equilibrium current at low bias-voltages, holds quantum-mechanical properties which are never achieved by classical mechanics.

Free Research Field

物性物理学理論