Theoretical studies of nonequilibrium open systems using nonperturbative approaches

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K13859
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 13020:Semiconductors, optical properties of condensed matter and atomic physics-related
• Research Institution: The University of Tokyo
• Principal Investigator: Ashida Yuto 東京大学, 大学院理学系研究科(理学部), 准教授 (00845464)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 量子多体物理 / 量子光学 / 共振器 / 繰り込み群 / 開放系 / 非エルミート系

Outline of Final Research Achievements

Conventional frameworks of condensed matter physics and statistical mechanics have had tremendous success in elucidating the laws and diverse phenomena of physical systems in thermal equilibrium. Meanwhile, the understanding of non-equilibrium open systems with inflow/dissipation of energy and matter is still in its infancy. While great progress has been made in the past few years in understanding regions where the coupling to the external environment is weak and the effects of the external environment can be treated perturbatively, the fundamental theory, let alone the physical phenomena that occur in strongly coupled nonperturbative regions, has not yet been developed. In this study, we have developed a fundamental theory describing non-equilibrium open systems that strongly interact with the external environment and for which nonperturbative treatment is essentially important, and have clarified the possibility of controlling material properties using cavity confinement.

Free Research Field

量子多体物理・量子光学

Academic Significance and Societal Importance of the Research Achievements

非平衡開放系は従来の統計物理や量子物理ではあまり考えられてこなかった新しい現象を発現する可能性を秘めた物理系で、近年世界中で盛んに研究がなされています。本研究により開放系の研究をこれまで取り扱いが困難と考えられてきた非摂動領域に展開するための端緒が得られました。特に、共振器を用いた物性制御の可能性が理論的に本研究で明らかとなりました。将来的にはこれらの成果が量子デバイスの制御やデコヒーレンスの抑制に向けた指針を与えるものと期待します。