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A non-relativistic system such as an ultracold trapped ion may perform a quantum simulation of a Dirac equation dynamics under specific conditions. The resulting Hamiltonian and dynamics are highly controllable, but the coupling between…

Quantum Physics · Physics 2017-02-24 Xue-Ke Song , Fu-Guo Deng , Lucas Lamata , J. G. Muga

Quantum many-body systems are emerging as key elements in the quest for quantum-based technologies and in the study of fundamental physics. In this study, we address the challenge of achieving fast and high-fidelity evolutions across…

Quantum Physics · Physics 2024-07-31 Hilario Espinós , Loris Maria Cangemi , Amikam Levy , Ricardo Puebla , Erik Torrontegui

The assumption that quantum systems relax to a stationary state in the long-time limit underpins statistical physics and much of our intuitive understanding of scientific phenomena. For isolated systems this follows from the eigenstate…

Quantum Physics · Physics 2019-04-16 Berislav Buca , Joseph Tindall , Dieter Jaksch

Control of multi-level quantum systems is sensitive to implementation errors in the control field and uncertainties associated with system Hamiltonian parameters. A small variation in the control field spectrum or the system Hamiltonian can…

Quantum Physics · Physics 2015-06-23 Andy Koswara , Raj Chakrabarti

We consider a bipartite quantum object, composed of a quantum system and a quantum actuator which is periodically reset. We show that the reduced dynamics of the system approaches unitarity as the reset frequency of the actuator is…

Quantum Physics · Physics 2016-04-05 David Layden , Eduardo Martin-Martinez , Achim Kempf

We study the Hamiltonian-independent contribution to the complexity of quantum optimal control problems. The optimization of controls that steer quantum systems to desired objectives can itself be considered a classical dynamical system…

Quantum Physics · Physics 2007-08-28 Raj Chakrabarti , Rebing Wu , Herschel Rabitz

Quantum systems can be controlled by other quantum systems in a reversible way, without any information leaking to the outside of the system-controller compound. Such coherent quantum control is deterministic, is less noisy than…

Quantum Physics · Physics 2021-12-28 Thomas Konrad , Amy Rouillard , Michael Kastner , Hermann Uys

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

The quantum brachistochrone problem addresses the fundamental challenge of achieving the quantum speed limit in applications aiming to realize a given unitary operation in a quantum system. Specifically, it looks into optimization of the…

Quantum Physics · Physics 2024-05-24 S. Malikis , V. Cheianov

Nonequilibrium states of closed quantum many-body systems defy a thermodynamic description. As a consequence, constraints such as the principle of equal a priori probabilities in the microcanonical ensemble can be relaxed, which can lead to…

Statistical Mechanics · Physics 2019-03-27 Markus Heyl

Quantum many-body devices suffer from imperfections that destabilize dynamics and limit scalability. We show that the dynamical growth of entanglement can intrinsically protect generic quantum dynamics against coherent and perturbative…

Quantum Physics · Physics 2026-02-25 Tianfeng Feng , Yue Cao , Wenjun Yu , Junkai Zeng , Xiaopeng Li , Xiu-Hao Deng , Qi Zhao

We show that every finite-dimensional quantum system with Markovian (i.e., GKLS-generated) time evolution has an autonomous unitary dilation which can be dynamically decoupled. Since there is also always an autonomous unitary dilation which…

Mathematical Physics · Physics 2023-01-18 Daniel Burgarth , Paolo Facchi , Robin Hillier

Identifying and classifying quantum phases from measurable time series in many-body dynamics have significant values, yet face formidable challenges, requiring profound knowledge of physicists. Here, to achieve a pure data-driven machine…

Mesoscale and Nanoscale Physics · Physics 2026-03-02 Zhaoran Feng , Jiangzhi Chen , Ce Wang , Jie Ren

We extend the concept of quantum speed limit -- the minimal time needed to perform a driven evolution -- to complex interacting many-body systems. We investigate a prototypical many-body system, a bosonic Josephson junction, at increasing…

Recent developments in quantum gas microscopy open up the possibility of real-time observation of quantum many-body systems. To understand the dynamics of atoms under such circumstances, we formulate the dynamics under a real-time spatially…

Quantum Physics · Physics 2017-03-01 Yuto Ashida , Masahito Ueda

We present a theory for the dynamical evolution of a quantum system coupled to a complex many-body intrinsic system/environment. By modelling the intrinsic many-body system with parametric random matrices, we study the types of effective…

Nuclear Theory · Physics 2009-10-30 Aurel Bulgac , Gui DoDang , Dimitri Kusnezov

The dynamics of an open quantum system can be fully described and tomographically reconstructed if the experimenter has complete control over the system of interest. Most real-world experiments do not fulfill this assumption, and the amount…

Quantum Physics · Physics 2018-07-09 Simon Milz , Felix A. Pollock , Kavan Modi

The physics of a closed quantum mechanical system is governed by its Hamiltonian. However, in most practical situations, this Hamiltonian is not precisely known, and ultimately all there is are data obtained from measurements on the system.…

A closed quantum system is defined as completely controllable if an arbitrary unitary transformation can be executed using the available controls. In practice, control fields are a source of unavoidable noise. Can one design control fields…

Quantum Physics · Physics 2015-05-27 Michael Khasin , Ronnie Kosloff

The objective of this article is to apply recent developments in geometric optimal control to analyze the time minimum control problem of dissipative two-level quantum systems whose dynamics is governed by the Lindblad equation. We focus…

Mathematical Physics · Physics 2008-09-25 B. Bonnard , D. Sugny