Theoretical studies on quantum pumping effect encircling the Liouvillian exceptional point

2023 Fiscal Year Final Research Report

• Project/Area Number: 19K14611
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 13010:Mathematical physics and fundamental theory of condensed matter physics-related
• Research Institution: University of Yamanashi
• Principal Investigator: Hashimoto Kazunari 山梨大学, 大学院総合研究部, 准教授 (10754591)
• Project Period (FY): 2019-04-01 – 2024-03-31
• Keywords: 非エルミート / 例外点 / メゾスコピック系

Outline of Final Research Achievements

I have studied the physical effects of Liouvillian exceptional points on the electron transport in a mesoscopic system consisting of two electrodes and a coupled quantum dot. In the study of the effect on electron pumping effects, I analyzed the effect on non-adiabatic electron pumping including the effect of relaxation modes, considering that the exception point appears in relaxation modes with finite real part (relaxation rate), and clarified the existence of Landau-Zener oscillations in the transient electron flow caused by the exception point. In addition, in the study of the effect on the steady-state current noise, it was found that the exceptional point gives a non-Lorentzian lineshape to the noise spectrum.

Free Research Field

非平衡統計力学

Academic Significance and Societal Importance of the Research Achievements

本研究の学術的意義は、メゾスコピック系の電子輸送という基礎的にも応用上も重要な物理現象に対するリウビリアン例外点の影響を明らかにした点にあると考える．特に、定常電流ノイズスペクトル線形と例外点の次数との対応関係の発見は、メゾスコピック系におけるリウビリアン例外点の実験的検出および分析において定常電流ノイズが有用なツールであることを初めて指摘したものであり、今後のリウビリアン例外点の実験的研究への波及効果が期待できる．