Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:1305.4724 · Journal of Physics A Mathematical and Theoretical

How fast and robust is the quantum adiabatic passage?

Kazutaka Takahashi

Published Jul 17, 2013• 28 citations
arXivHTMLPDF

Abstract

We study the assisted adiabatic passage, and equivalently the transitionless quantum driving, as a quantum brachistochrone trajectory. The optimal Hamiltonian for given constraints is constructed from the quantum brachistochrone equation. We discuss how the adiabatic passage is realized as the solution of the equation. The formulation of the quantum brachistochrone is based on the principle of least action. We utilize it to discuss the stability of the adiabatic passage.

DOI
10.1088/1751-8113/46/31/315304

Related papers

Minimum-Time Quantum Control and the Quantum Brachistochrone Equation

Jing Yang, Adolfo del Campo

Minimum-time quantum control protocols can be obtained from the quantum brachistochrone formalism [Carlini, Hosoya, Koike, and Okudaira, Phys. Rev. Lett. 96, 06053, (2006)]. We point out that the original treatment implicitly applied the variational calculus with fixed boundary conditions. We argue that the genuine quantum brachistochrone problem involves a variational problem with a movable endpoint, contrary to the classical brachistochrone problem. This formulation not only simplifies the derivation of the quantum brachistochrone equation but introduces an additional constraint at the endpoint due to the boundary effect. We present the general solution to the full quantum brachistochrone equation and discuss its main features. Using it, we prove that the speed of evolution under constraints is reduced with respect to the unrestricted case. In addition, we find that solving the quantum brachistochrone equation is closely connected to solving the dynamics of the Lagrange multipliers, which is in general governed by nonlinear differential equations. Their numerical integration allows generating time-extremal trajectories. Furthermore, when the restricted operators form a closed subalgebra, the Lagrange multipliers become constant and the optimal Hamiltonian takes a concise form. The new class of analytically solvable models for the quantum brachistochrone problem opens up the possibility of applying it to many-body quantum systems, exploring notions related to geometry such as quantum speed limits, and advancing significantly the quantum state and gate preparation for quantum information processing.

arXiv:2204.12792•Apr 27, 2022•2 citations

Quantum brachistochrone

Tatsuhiko Koike

Quantum brachistochrone (QB) is a quantum analogue of classical brachistochrone (shortest path). It is a solution to the following problem: How can we perform a desired quantum operation (or obtain a desired final quantum state) most quickly, by a time-dependent Hamiltonian subject to given constraints? Finding QB is a fundamental problem in quantum mechanics in its own right. Moreover, it will be useful in the study of quantum information and quantum engineering, such as quantum speed limits and implementations of quantum computers. A general framework for finding QBs, called QB formalism, has been developed. It is based on Pontryagin's maximum principle. We review the basics of the QB formalism, give simple examples, and briefly discuss some related studies. This article is part of the theme issue 'Shortcuts to adiabaticity: theoretical, experimental and interdisciplinary perspectives'.

Philosophical Transactions of the Royal Society A Mathematical Physical and Engineering Sciences•Nov 6, 2022•12 citations

Quantum adiabatic brachistochrone for open systems

Alan C. Santos, Celso J. Villas-Bôas, Romain Bachelard

We propose a variational principle to compute a quantum adiabatic brachistochrone (QAB) for open systems. Using the notion of ``adiabatic speed'' based on the energy gaps, we derive a Lagrangian associated to the functional measuring the time spent to achieve adiabatic behavior, which in turn allows us to perform the optimization. The QAB is illustrated for the nonunitary dynamics of a stimulated Raman adiabatic passage process, the Deutsch-Jozsa quantum computing algorithm, and of a transmon qutrit. A numerical protocol is devised, which allows one to compute the QAB for arbitrary quantum systems for which exact simulations can be afforded. We also establish sufficient conditions for the equivalence between the Lagrangians, and thus the QAB, of open and closed systems.

arXiv:2006.13718•Physical Review A•Jan 11, 2021•7 citations

Highly Adiabatic Time-Optimal Quantum Driving at Low Energy Cost

Lluc Garcia, Josep María Bofill, Ibério de P. R. Moreira +1 more

Time-efficient control schemes for manipulating quantum systems are of great importance in quantum technologies, where environmental forces rapidly degrade the quality of pure states over time. In this Letter, we formulate an approach to time-optimal control that circumvents the boundary-value problem that plagues the quantum brachistochrone equation at the expense of relaxing the form of the control Hamiltonian. In this setting, a coupled system of equations, one for the control Hamiltonian and another one for the duration of the protocol, realizes an ansatz-free approach to quantum control theory. We show how driven systems, in the form of a Landau-Zener type Hamiltonian, can be efficiently maneuvered to speed up a given state transformation in a highly adiabatic manner and with a low energy cost.

Physical Review Letters•Oct 26, 2022•12 citations

Time-Optimal Quantum Evolution

A. Carlini, Akio Hosoya, Tatsuhiko Koike +1 more

We present a general framework for finding the time-optimal evolution and the optimal Hamiltonian for a quantum system with a given set of initial and final states. Our formulation is based on the variational principle and is analogous to that for the brachistochrone in classical mechanics. We reduce the problem to a formal equation for the Hamiltonian which depends on certain constraint functions specifying the range of available Hamiltonians. For some simple examples of the constraints, we explicitly find the optimal solutions.

arXiv:quant-ph/0511039•Physical Review Letters•Feb 15, 2006•311 citations

Fast and Robust Quantum State Transfer via Optimal Transitionless Quantum Driving

Chun‐Ling Zhang, Xiu‐Min Lin

Abstract For the past few years, shortcuts to adiabaticity have attracted great attention since they can avoid the necessity of slow driving for adiabatic method while inheriting the partial robustness of the adiabatic dynamics. In this paper, a universal approach to implement quantum state transfer in a three‐state system via optimal transitionless quantum driving is presented. The fast path is optimized for great robustness against uncontrolled systematic error by selecting appropriate experimental parameters. The robustness of the protocol is discussed via numerical simulations. Compared with conventional transitionless quantum driving and adiabatic passage, the protocol via optimized transitionless quantum driving possesses more robustness against the systematic error. Furthermore, decoherence arising from atomic spontaneous emission and dephasing only has a slight impact on the fidelity of quantum state transfer. This work opens up a new avenue for high‐fidelity quantum state transfer in the case of the uncontrolled errors.

Annalen der Physik•May 11, 2022•1 citation
We study the assisted adiabatic passage, and equivalently the transitionless quantum driving, as a quantum brachistochrone trajectory. The optimal Hamiltonian for given constraints is constructed from the quantum brachistochrone equation. We discuss how the adiabatic passage is realized as the solution of the equation. The formulation of the quantum brachistochrone is based on the principle of least action. We utilize it to discuss the stability of the adiabatic passage.
Minimum-time quantum control protocols can be obtained from the quantum brachistochrone formalism [Carlini, Hosoya, Koike, and Okudaira, Phys. Rev. Lett. 96, 06053, (2006)]. We point out that the original treatment implicitly applied the variational calculus with fixed boundary conditions. We argue that the genuine quantum brachistochrone problem involves a variational problem with a movable endpoint, contrary to the classical brachistochrone problem. This formulation not only simplifies the derivation of the quantum brachistochrone equation but introduces an additional constraint at the endpoint due to the boundary effect. We present the general solution to the full quantum brachistochrone equation and discuss its main features. Using it, we prove that the speed of evolution under constraints is reduced with respect to the unrestricted case. In addition, we find that solving the quantum brachistochrone equation is closely connected to solving the dynamics of the Lagrange multipliers, which is in general governed by nonlinear differential equations. Their numerical integration allows generating time-extremal trajectories. Furthermore, when the restricted operators form a closed subalgebra, the Lagrange multipliers become constant and the optimal Hamiltonian takes a concise form. The new class of analytically solvable models for the quantum brachistochrone problem opens up the possibility of applying it to many-body quantum systems, exploring notions related to geometry such as quantum speed limits, and advancing significantly the quantum state and gate preparation for quantum information processing.
Quantum brachistochrone (QB) is a quantum analogue of classical brachistochrone (shortest path). It is a solution to the following problem: How can we perform a desired quantum operation (or obtain a desired final quantum state) most quickly, by a time-dependent Hamiltonian subject to given constraints? Finding QB is a fundamental problem in quantum mechanics in its own right. Moreover, it will be useful in the study of quantum information and quantum engineering, such as quantum speed limits and implementations of quantum computers. A general framework for finding QBs, called QB formalism, has been developed. It is based on Pontryagin's maximum principle. We review the basics of the QB formalism, give simple examples, and briefly discuss some related studies. This article is part of the theme issue 'Shortcuts to adiabaticity: theoretical, experimental and interdisciplinary perspectives'.
We propose a variational principle to compute a quantum adiabatic brachistochrone (QAB) for open systems. Using the notion of ``adiabatic speed'' based on the energy gaps, we derive a Lagrangian associated to the functional measuring the time spent to achieve adiabatic behavior, which in turn allows us to perform the optimization. The QAB is illustrated for the nonunitary dynamics of a stimulated Raman adiabatic passage process, the Deutsch-Jozsa quantum computing algorithm, and of a transmon qutrit. A numerical protocol is devised, which allows one to compute the QAB for arbitrary quantum systems for which exact simulations can be afforded. We also establish sufficient conditions for the equivalence between the Lagrangians, and thus the QAB, of open and closed systems.
Time-efficient control schemes for manipulating quantum systems are of great importance in quantum technologies, where environmental forces rapidly degrade the quality of pure states over time. In this Letter, we formulate an approach to time-optimal control that circumvents the boundary-value problem that plagues the quantum brachistochrone equation at the expense of relaxing the form of the control Hamiltonian. In this setting, a coupled system of equations, one for the control Hamiltonian and another one for the duration of the protocol, realizes an ansatz-free approach to quantum control theory. We show how driven systems, in the form of a Landau-Zener type Hamiltonian, can be efficiently maneuvered to speed up a given state transformation in a highly adiabatic manner and with a low energy cost.
We present a general framework for finding the time-optimal evolution and the optimal Hamiltonian for a quantum system with a given set of initial and final states. Our formulation is based on the variational principle and is analogous to that for the brachistochrone in classical mechanics. We reduce the problem to a formal equation for the Hamiltonian which depends on certain constraint functions specifying the range of available Hamiltonians. For some simple examples of the constraints, we explicitly find the optimal solutions.
Abstract For the past few years, shortcuts to adiabaticity have attracted great attention since they can avoid the necessity of slow driving for adiabatic method while inheriting the partial robustness of the adiabatic dynamics. In this paper, a universal approach to implement quantum state transfer in a three‐state system via optimal transitionless quantum driving is presented. The fast path is optimized for great robustness against uncontrolled systematic error by selecting appropriate experimental parameters. The robustness of the protocol is discussed via numerical simulations. Compared with conventional transitionless quantum driving and adiabatic passage, the protocol via optimized transitionless quantum driving possesses more robustness against the systematic error. Furthermore, decoherence arising from atomic spontaneous emission and dephasing only has a slight impact on the fidelity of quantum state transfer. This work opens up a new avenue for high‐fidelity quantum state transfer in the case of the uncontrolled errors.