Control of open quantum many-body systems via nonequilibrium driving

2022 Fiscal Year Final Research Report

• Project/Area Number: 19K14622
• 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: Institute of Physical and Chemical Research
• Principal Investigator: Mori Takashi 国立研究開発法人理化学研究所, 創発物性科学研究センター, 研究員 (00647761)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: 開放量子系 / 非平衡統計力学 / 量子多体系 / フロケ理論 / リウビリアンギャップ

Outline of Final Research Achievements

We have investigated general properties of quantum many-body systems under dissipation or external driving fields. We studied the steady state in many-body quantum system in a weak contact with a nonequilibrium environment. It is shown that the eigenstate thermalization hypothesis, which is an important property of isolated quantum systems, plays a key role in the steady state under dissipation. We also investigated how the relaxation time of open quantum many-body systems is determined from the spectral decomposition of the Liouvillian superoperator, which is a generator of the Markovian dissipative time evolution. Furthermore, we analytically calculated the energy absorption rate of quantum many-body systems subject to time-periodic, quasi-periodic, and random driving fields beyond the linear response regime.

Free Research Field

統計物理学

Academic Significance and Societal Importance of the Research Achievements

散逸や外場駆動のもとでの量子多体系の非平衡ダイナミクスの一般的な性質を明らかにすることは、統計物理学、固体物理学、原子・分子・光科学、さらには高エネルギー物理、量子情報に至るまで、物理学の広い領域で重要となる基礎的な問題である。本研究は、このような量子多体系の非平衡ダイナミクスの一般的な性質のいくつかを明らかにしたもので、今後の量子物理学の発展にとって基礎的な成果を得ることができた。