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Quantum control aims to manipulate quantum systems toward specific quantum states or desired operations. Designing highly accurate and effective control steps is vitally important to various quantum applications, including energy…

Quantum Physics · Physics 2023-01-11 Xinyu Fei , Lucas T. Brady , Jeffrey Larson , Sven Leyffer , Siqian Shen

Fifty years of developments in nuclear magnetic resonance (NMR) have resulted in an unrivaled degree of control of the dynamics of coupled two-level quantum systems. This coherent control of nuclear spin dynamics has recently been taken to…

Quantum Physics · Physics 2015-06-26 Lieven M. K. Vandersypen , Isaac L. Chuang

Fast control of quantum systems is essential in order to make use of quantum properties before they are degraded by decoherence. This is important for quantum-enhanced information processing, as well as for pushing quantum systems into…

Quantum Physics · Physics 2016-04-12 J. Alonso , F. M. Leupold , Z. U. Soler , M. Fadel , M. Marinelli , B. C. Keitch , V. Negnevitsky , J. P. Home

In this paper, we present efficient quantum algorithms that are exponentially faster than classical algorithms for solving the quantum optimal control problem. This problem involves finding the control variable that maximizes a physical…

Quantum Physics · Physics 2023-10-02 Xiantao Li , Chunhao Wang

A new formalism for the optimal control of quantum mechanical physical observables is presented. This approach is based on an analogous classical control technique reported previously[J. Botina, H. Rabitz and N. Rahman, J. chem. Phys. Vol.…

Chemical Physics · Physics 2009-10-30 Jair Botina , Herschel Rabitz , Naseem Rahman

The quantum search problem is an important problem due to the fact that a general NP problem can be solved efficiently by an unsorted quantum search algorithm. Here it has been shown that the quantum search problem could be solved in…

Quantum Physics · Physics 2007-05-23 Xijia Miao

We consider the optimal control of quantum systems interacting non-linearly with an electromagnetic field. We propose new monotonically convergent algorithms to solve the optimal equations. The monotonic behavior of the algorithm is ensured…

Quantum Physics · Physics 2015-05-13 M. Lapert , R. Tehini , G. Turinici , D. Sugny

The standard quantum search algorithm lacks a feature, enjoyed by many classical algorithms, of having a fixed-point, i.e. a monotonic convergence towards the solution. Here we present two variations of the quantum search algorithm, which…

Quantum Physics · Physics 2007-05-23 Lov K. Grover , Apoorva Patel , Tathagat Tulsi

The paper examines the prominent algorithm D-MORPH to search for the optimal control of a quantum system in order to implement desired unitary evolution of the quantum system at the final time, and reveals new mathematical expressions for…

Quantum Physics · Physics 2017-09-19 Konstantin Zhdanov

Errors in the control of quantum systems may be classified as unitary, decoherent and incoherent. Unitary errors are systematic, and result in a density matrix that differs from the desired one by a unitary operation. Decoherent errors…

Quantum control for error correction is critical for the practical use of quantum computers. We address quantum optimal control for single-shot multi-qubit gates by framing as a feasibility problem for the Hamiltonian model and then solving…

Quantum Physics · Physics 2019-05-07 Raymond J. Spiteri , Marina Schmidt , Joydip Ghosh , Ehsan Zahedinejad , Barry C. Sanders

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

The angular momentum of molecules, or, equivalently, their rotation in three-dimensional space, is ideally suited for quantum control. Molecular angular momentum is naturally quantized, time evolution is governed by a well-known Hamiltonian…

Quantum Physics · Physics 2019-10-23 Christiane P. Koch , Mikhail Lemeshko , Dominique Sugny

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

Simple, precise, and robust control is demanded for operating a large quantum information processor. However, existing routes to high-fidelity quantum control rely heavily on arbitrary waveform generators that are difficult to scale up.…

Quantum Physics · Physics 2022-09-21 Qi-Ming Chen , Herschel Rabitz , Re-Bing Wu

The optimal runtime of a quantum computer searching a database is typically cited as the square root of the number of items in the database, which is famously achieved by Grover's algorithm. With parallel oracles, however, it is possible to…

The optimal quantum control theory is employed to determine electric pulses capable of producing quantum gates with high fidelity (higher than 0.9997). Particularly, these quantum gates were chosen to perform the permutation algorithm (Z.…

Quantum Physics · Physics 2018-03-28 C. M. Rivera-Ruiz , E. F. de Lima , F. F. Fanchini , V. Lopez-Richard , L. K. Castelano

In building a quantum information processor (QIP), the challenge is to coherently control a large quantum system well enough to perform an arbitrary quantum algorithm and to be able to correct errors induced by decoherence. Nuclear magnetic…

Quantum Physics · Physics 2009-11-13 C. A. Ryan , C. Negrevergne , M. Laforest , E. Knill , R. Laflamme

We investigate the optimal charging processes for several models of quantum batteries, finding how to maximize the energy stored in a given battery with a finite-time modulation of a set of external fields. We approach the problem using…

We demonstrate how quantum optimal control can be used to enhance quantum resources for bipartite one-way protocols, specifically EPR-steering with qubit measurements. Steering is relevant for one-sided device-independent key distribution,…

Quantum Physics · Physics 2016-03-09 Jukka Kiukas , Daniel Burgarth