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Related papers: Time Optimal Qubit Computer

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We address the problem of cooling a Markovian quantum system to a pure state in the shortest amount of time possible. Here the system drift takes the form of a Lindblad master equation and we assume fast unitary control. This setting allows…

Quantum Physics · Physics 2024-03-11 Emanuel Malvetti

Optimal control theory is a versatile tool that presents a route to significantly improving figures of merit for quantum information tasks. We combine it here with the geometric theory for local equivalence classes of two-qubit operations…

Quantum Physics · Physics 2015-03-19 M. M. Müller , D. M. Reich , M. Murphy , H. Yuan , J. Vala , K. B. Whaley , T. Calarco , C. P. Koch

Optimally-shaped electromagnetic fields have the capacity to coherently control the dynamics of quantum systems and thus offer a promising means for controlling molecular transformations relevant to chemical, biological, and materials…

Quantum Physics · Physics 2021-06-08 Alicia B. Magann , Matthew D. Grace , Herschel A. Rabitz , Mohan Sarovar

Quantum computation is based on implementing selected unitary transformations which represent algorithms. A generalized optimal control theory is used to find the driving field that generates a prespecified unitary transformation. The…

Quantum Physics · Physics 2009-11-07 Jose P. Palao , Ronnie Kosloff

The optimal time for the controllability of linear hyperbolic systems in one dimensional space with one-side controls has been obtained recently for time-independent coefficients in our previous works. In this paper, we consider linear…

Optimization and Control · Mathematics 2021-03-05 Jean-Michel Coron , Hoai-Minh Nguyen

A systematic scheme is proposed to numerically estimate the quantum speed limit and temporal shape of optimal control in two-level and three-level quantum systems with bounded amplitude. For the two-level system, two quantum state…

Quantum Physics · Physics 2023-05-02 Xikun Li

This paper is concerned with the linear quadratic optimal control of discrete-time time-varying system with terminal state constraint. The main contribution is to propose a Q-learning algorithm for the optimal controller when the…

Optimization and Control · Mathematics 2023-07-20 Juanjuan Xu , Jingmei Liu , Zhaorong Zhang , Wei Wang

The quantum speed limit sets the minimum time required to transfer a quantum system completely into a given target state. At shorter times the higher operation speed has to be paid with a loss of fidelity. Here we quantify the trade-off…

Quantum Physics · Physics 2015-12-08 Miroslav Gajdacz , Kunal K. Das , Jan Arlt , Jacob F. Sherson , Tomáš Opatrný

Quantum brachistochrone method has recently emerged as a technique allowing one to implement the desired unitary evolution operator in a physical system within the minimal time. Here, we apply this approach to the problem of time-optimal…

Mesoscale and Nanoscale Physics · Physics 2025-06-10 Kseniia S. Chernova , Andrei A. Stepanenko , Maxim A. Gorlach

We study the time-optimal robust control of a two-level quantum system subjected to field inhomogeneities. We apply the Pontryagin Maximum Principle and we introduce a reduced space onto which the optimal dynamics is projected down. This…

Quantum Physics · Physics 2025-09-03 O. Fresse-Colson , S. Guérin , Xi Chen , D. Sugny

This paper studies the time optimal control problem for systems of heat equations coupled by a pair of constant matrices. The control constraint is of the ball-type, while the target is the origin of the state space. We obtain an upper…

Optimization and Control · Mathematics 2020-07-29 Shulin Qin , Gengsheng Wang , Huaiqiang Yu

Information processing, quantum or classical, relies on channels transforming multiple input states to different corresponding outputs. Previous research has established bounds on the thermodynamic resources required for such operations,…

Quantum Physics · Physics 2024-05-22 Joe Dunlop , Federico Cerisola , Jorge Tabanera-Bravo , Janet Anders

In this paper, we demonstrate that optimal control algorithms can be used to speed up the implementation of modules of quantum algorithms or quantum simulations in networks of coupled qubits. The gain is most prominent in realistic cases,…

Quantum Physics · Physics 2008-12-20 T. Schulte-Herbrueggen , A. K. Spoerl , N. Khaneja , S. J. Glaser

The simulation of quantum dynamics on a digital quantum computer with parameterized circuits has widespread applications in fundamental and applied physics and chemistry. In this context, using the hybrid quantum-classical algorithm,…

Quantum Physics · Physics 2023-07-19 Tangyou Huang , Yongcheng Ding , Léonce Dupays , Yue Ban , Man-Hong Yung , Adolfo del Campo , Xi Chen

We combine a quantum dynamical propagator that explicitly accounts for quantum mechanical time ordering with optimal control theory. After analyzing its performance with a simple model, we apply it to a superconducting circuit under…

Quantum Physics · Physics 2018-08-02 Daniel Basilewitsch , Lutz Marder , Christiane P. Koch

In this study, we theoretically analyzed a control protocol based on ``time-dependent resonance" in nearly adiabatic two-level quantum systems, demonstrating that it exhibits properties equivalent to adiabatic control. This protocol is…

Quantum Physics · Physics 2025-01-03 Takayuki Suzuki

We consider the optimal control problem in a two-qubit system with bounded amplitude. Two cases are studied: quantum state preparation and entanglement creation. Cost functions, fidelity and concurrence, are optimized over bang-off controls…

Quantum Physics · Physics 2023-02-08 Xikun Li

Quantum state control is a fundamental tool for quantum technologies. In this work, we propose and analyze the use of quantum optimal control to exploit the dipolar interaction of ultracold atoms on a lattice ring, focusing on the…

A New theoretical formalism for the optimal quantum control has been presented. The approach stems from the consideration of describing the time-dependent quantum system in terms of the real physical observables, viz., the probability…

Chemical Physics · Physics 2015-06-26 Bijoy K. Dey

We discuss experimental situations that consist of multiple preparation and measurement stages. This leads us to a new approach to quantum mechanics. In particular, we introduce the idea of multi-time quantum states which are the…

Quantum Physics · Physics 2013-05-29 Y. Aharonov , S. Popescu , J. Tollaksen , L. Vaidman