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Related papers: Gradient flow for controlling quantum ensemble

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In this paper, we propose a novel probabilistic control framework for efficiently controlling an ensemble of quantum systems that can also compensate for the interaction of the systems with the external environment. The main challenge in…

Quantum Physics · Physics 2023-09-08 Randa Herzallah , Abdessamad Belfakir

Quantum computing requires the optimization of control pulses to achieve high-fidelity quantum gates. We propose a machine learning-based protocol to address the challenges of evaluating gradients and modeling complex system dynamics. By…

Quantum Physics · Physics 2026-01-27 Paul Surrey , Julian D. Teske , Tobias Hangleiter , Hendrik Bluhm , Pascal Cerfontaine

A quantum stochastic model for an open dynamical system (quantum receiver) and output multi-channel of observation with an additive nonvacuum quantum noise is given. A quantum stochastic Master equation for the corresponding instrument is…

Quantum Physics · Physics 2015-06-26 V. P. Belavkin

The gradient descent approach is the key ingredient in variational quantum algorithms and machine learning tasks, which is an optimization algorithm for finding a local minimum of an objective function. The quantum versions of gradient…

Quantum Physics · Physics 2022-04-19 Jin-Min Liang , Shi-Jie Wei , Shao-Ming Fei

A broad class of hybrid quantum-classical algorithms known as "variational algorithms" have been proposed in the context of quantum simulation, machine learning, and combinatorial optimization as a means of potentially achieving a quantum…

Quantum Physics · Physics 2021-04-09 Aram Harrow , John Napp

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

A number of important modern applications in optimal control can be formulated as open loop control problems in which the underlying dynamical systems are subject to random inputs. These so-called ensemble control problems require the…

Optimization and Control · Mathematics 2026-05-05 Alessandro Scagliotti , Thomas M. Surowiec

This paper considers the optimal control problem for realizing logical gates in a closed quantum system. The quantum state is governed by Schrodinger's equation, which we formulate as a time-dependent Hamiltonian system in terms of the real…

Many phenomena in physics, chemistry, and biology involve seeking an optimal control to maximize an objective for a classical or quantum system which is open and interacting with its environment. The complexity of finding an optimal control…

Quantum Physics · Physics 2010-11-08 Alexander Pechen , Herschel Rabitz

Optimizing the controls of quantum systems plays a crucial role in advancing quantum technologies. The time-varying noises in quantum systems and the widespread use of inhomogeneous quantum ensembles raise the need for high-quality quantum…

Quantum Physics · Physics 2025-05-06 Xinyu Fei , Lucas T. Brady , Jeffrey Larson , Sven Leyffer , Siqian Shen

For quantum systems with high purity, we find all observables that, when continuously monitored, maximize the instantaneous reduction in the von Neumann entropy. This allows us to obtain all locally optimal feedback protocols with strong…

Quantum Physics · Physics 2009-11-13 Alireza Shabani , Kurt Jacobs

We provide sufficient conditions for the approximate controllability of infinite-dimensional quantum control systems corresponding to form perturbations of the drift Hamiltonian modulated by a control function. We rely on previous results…

Optimization and Control · Mathematics 2025-04-02 Aitor Balmaseda , Davide Lonigro , Juan Manuel Pérez-Pardo

An exact and efficient new method to simulate dynamics in dissipative quantum systems is presented. A stochastic Liouville equation, deduced from Feynman and Vernon's path-integral expression of the reduced density matrix, is used to…

Statistical Mechanics · Physics 2009-10-31 J. Stockburger , C. H. Mak

Following the success of Moore's predictions, we are approaching a limit in the miniaturization of semiconductors for computing materials. This has led to the exploration of various research paths to develop alternative computing paradigms,…

Quantum Physics · Physics 2026-05-20 Dawit Hiluf Hailu

Symmetry constraints provide a powerful means to control the dynamics of open quantum systems. However, the set of accessible control parameters is often limited. Here, we show that a tunable phase in the collective light-matter coupling of…

Quantum Physics · Physics 2026-02-24 Marc Nairn , Beatriz Olmos , Parvinder Solanki

A procedure to find optimal regimes for quantum thermal engines (QTMs) is described and demonstrated. The QTMs are modelled as the periodically-driven non-equilibrium steady states of open quantum systems, whose dynamics is approximated in…

Quantum Physics · Physics 2024-10-10 Alberto Castro

A quantum system whose internal Hamiltonian is not strongly regular or/and control Hamiltonians are not full connected, are thought to be in the degenerate cases. In this paper, convergence problems of the multi-control Hamiltonians closed…

Systems and Control · Computer Science 2014-08-20 Shuang Cong , Fangfang Meng , Jianxiu Liu

At the heart of quantum technology development is the control of quantum systems at the level of individual quanta. Mathematically, this is realised through the study of Hamiltonians and the use of methods to solve the dynamics of quantum…

Quantum Physics · Physics 2022-10-24 Sofia Qvarfort , Igor Pikovski

In this paper we give a description of the asymptotic behavior, as $\epsilon\to 0$, of the $\epsilon$-gradient flow in the finite dimensional case. Under very general assumptions we prove that it converges to an evolution obtained by…

Functional Analysis · Mathematics 2007-05-23 Chiara Zanini

A Lyapunov-based approach for the trajectory generation of an $N$-dimensional Schr{\"o}dinger equation in whole $\RR^N$ is proposed. For the case of a quantum particle in an $N$-dimensional decaying potential the convergence is precisely…

Analysis of PDEs · Mathematics 2015-05-13 Mazyar Mirrahimi