Information-theoretic characterization of uncertainties of quantum systems and development of quantum robust control theory

2023 Fiscal Year Final Research Report

• Project/Area Number: 19K03619
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 12040:Applied mathematics and statistics-related
• Research Institution: Kyoto University
• Principal Investigator: Ohki Kentaro 京都大学, 情報学研究科, 助教 (40639233)
• Project Period (FY): 2019-04-01 – 2024-03-31
• Keywords: 適応制御 / ロバスト制御 / ロバスト安定化 / 量子制御

Outline of Final Research Achievements

This research addressed the control problem of uncertainty in quantum systems. The main results were a performance analysis of robust stabilization control for finite-dimensional quantum systems due to unexpected modeling errors and an extension of robust adaptive control to quantum systems. Because finite-dimensional quantum systems are commonly used as quantum information processing devices, providing effective control laws for such systems is crucial. In this research, we investigated the effect of uncertainty on stabilization control. We probabilistically evaluated the level of modeling error required to remain near the desired equilibrium point to which the system converges. We also clarified that when modeling errors are parametric, it is possible to converge to a specific equilibrium point by learning the parameters, regardless of the size of the error.

Free Research Field

量子制御

Academic Significance and Societal Importance of the Research Achievements

安定化制御のロバスト性解析は，平衡点を消失させないモデル化誤差を考えて行われることが多く，平衡点へ収束が原理的にできない場合の確率系に対する解析的な結果を得ることは本研究が初めてである．また，非線形確率系としてモデル化される量子系に対する適応制御の研究はこれまでになく，量子制御理論に新たな方向性を与えた．
また，これらの研究成果は，量子系の設計においてどの程度精密に作成しなければいけないかという設計指針を与え，実際のデバイス開発の指針を与えられるものと期待される．