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Related papers: FOCQS: Feedback Optimally Controlled Quantum State…

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Feedback loops are at the heart of most classical control procedures. A controller compares the signal measured by a sensor with the target value. It adjusts then an actuator in order to stabilize the signal towards its target. Generalizing…

This thesis addresses the problem of developing a quantum counter-part of the well established classical theory of control. We dwell on the fundamental fact that quantum states are generally not perfectly distinguishable, and quantum…

Quantum Physics · Physics 2009-08-21 Paulo E. M. F. Mendonca

Communicating classical information with a quantum system involves the receiver making a measurement on the system so as to distinguish as well as possible the alphabet of states used by the sender. We consider the situation in which this…

Quantum Physics · Physics 2007-05-23 Kurt Jacobs

We describe a scheme for quantum error correction that employs feedback and weak measurement rather than the standard tools of projective measurement and fast controlled unitary gates. The advantage of this scheme over previous protocols…

Quantum Physics · Physics 2009-11-10 Mohan Sarovar , Charlene Ahn , Kurt Jacobs , Gerard J. Milburn

A central challenge in quantum computing is to identify more computational problems for which utilization of quantum resources can offer significant speedup. Here, we propose a hybrid quantum-classical scheme to tackle the quantum optimal…

Quantum Physics · Physics 2017-04-19 Jun Li , Xiaodong Yang , Xinhua Peng , Chang-Pu Sun

We present a formulation of feedback in quantum systems in which the best estimates of the dynamical variables are obtained continuously from the measurement record, and fed back to control the system. We apply this method to the problem of…

Quantum Physics · Physics 2009-10-31 A. C. Doherty , K. Jacobs

Hybrid quantum-classical algorithms hold great promise for solving quantum control problems on near-term quantum computers. In this work, we employ the hybrid framework that integrates digital quantum simulation with classical optimization…

Quantum Physics · Physics 2025-07-01 Tangyou Huang , Jing-Jun Zhu , Zhong-Yi Ni

In recent quantum algorithmic developments, a feedback-based approach has shown promise for preparing quantum many-body system ground states and solving combinatorial optimization problems. This method utilizes quantum Lyapunov control to…

Quantum controls realize the unitary or nonunitary operations employed in quantum computers, quantum simulators, quantum communications, and other quantum information devices. They implement the desired quantum dynamics with the help of…

Quantum Physics · Physics 2022-06-02 T S Mahesh , Priya Batra , M. Harshanth Ram

Quantum optimal control represents a powerful technique to enhance the performance of quantum experiments by engineering the controllable parameters of the Hamiltonian. However, the computational overhead for the necessary optimization of…

Feedback control of quantum mechanical systems must take into account the probabilistic nature of quantum measurement. We formulate quantum feedback control as a problem of stochastic nonlinear control by considering separately a quantum…

Quantum Physics · Physics 2007-05-23 Ramon van Handel , John K. Stockton , Hideo Mabuchi

Preparing fractional quantum Hall (FQH) states represents a key challenge for quantum simulators. While small Laughlin-type states have been realized by manipulating two atoms or two photons, scaling up these settings to larger ensembles…

Quantum Gases · Physics 2025-07-14 Ling-Na Wu , Xikun Li , Nathan Goldman , Botao Wang

Feedback control protocols can stabilize and enhance the operation of quantum devices, however, unavoidable delays in the feedback loop adversely affect their performance. We introduce a quantum control methodology, combining open-loop…

Quantum Physics · Physics 2010-03-25 Joshua Combes , Howard M. Wiseman , A. J. Scott

Recently, large language models (LLMs) have achieved significant progress in automated code generation. Despite their strong instruction-following capabilities, these models frequently struggled to align with user intent in coding…

Machine Learning · Computer Science 2025-06-23 Zeyuan Li , Yangfan He , Lewei He , Jianhui Wang , Tianyu Shi , Bin Lei , Yuchen Li , Qiuwu Chen

Preparing desired quantum states and quantum operations (processes) is essential for numerous tasks in quantum computation. Several approaches have been developed for optimal control of quantum states, whereas optimal strategies for…

Quantum Physics · Physics 2025-09-29 M. Farnia , V. Rezvani , A. T. Rezakhani

The importance of feedback control is being increasingly appreciated in quantum physics and applications. This paper describes the use of optimal control methods in the design of quantum feedback control systems, and in particular the paper…

Quantum Physics · Physics 2009-11-10 M. R. James

The protection of quantum states is challenging for non-orthogonal states especially in the presence of noises. The recent research breakthrough shows that this difficulty can be overcome by feedback control with weak measurements. However,…

Quantum Physics · Physics 2015-06-16 Y. Yang , X. Y. Zhang , J. Ma , X. X. Yi

Efficiently controlling linear Gaussian quantum (LGQ) systems is a significant task in both the study of fundamental quantum theory and the development of modern quantum technology. Here, we propose a general quantum-learning-control method…

Quantum Physics · Physics 2024-06-11 Yu-Hong Liu , Yexiong Zeng , Qing-Shou Tan , Daoyi Dong , Franco Nori , Jie-Qiao Liao

We present a general approach to measurement-based quantum feedback that employs proportional and quantum state-based (PaQS) feedback components to obtain locally optimal protocols. To demonstrate the power of the method, we first show that…

Quantum Physics · Physics 2020-12-23 Song Zhang , Leigh Martin , K. Birgitta Whaley

Quantum variational algorithms have garnered significant interest recently, due to their feasibility of being implemented and tested on noisy intermediate scale quantum (NISQ) devices. We examine the robustness of the quantum approximate…

Quantum Physics · Physics 2019-11-05 Yulong Dong , Xiang Meng , Lin Lin , Robert Kosut , K. Birgitta Whaley