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Related papers: Quantum switch instabilities with an open control

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Ising interaction between qubits could produce distortion in entangled pairs generated for engineering purposes (as in quantum computation) in presence of parasite magnetic fields, destroying or altering the expected behavior of process in…

Quantum Physics · Physics 2013-05-29 Francisco Delgado

Causal reasoning is essential to science, yet quantum theory challenges it. Quantum correlations violating Bell inequalities defy satisfactory causal explanations within the framework of classical causal models. What is more, a theory…

Quantum Physics · Physics 2021-03-05 Jonathan Barrett , Robin Lorenz , Ognyan Oreshkov

Precisely characterizing and controlling realistic open quantum systems is one of the most challenging and exciting frontiers in quantum sciences and technologies. In this Letter, we present methods of approximately computing reachable sets…

Quantum Physics · Physics 2016-07-13 Jun Li , Dawei Lu , Zhihuang Luo , Raymond Laflamme , Xinhua Peng , Jiangfeng Du

Two quantum measurements sequentially acting one after the other, if they are mutually unbiased, will lead to a complete removal of information encoded in the input quantum state. We find that if the order of the two sequential measurements…

Quantum Physics · Physics 2019-10-01 Manish K. Gupta , Ujjwal Sen

Nature, in the form of dissipation, inevitably intervenes in our efforts to control a quantum system. In this talk we show that although we cannot, in general, compensate for dissipation by coherent control of the system, such effects are…

Quantum Physics · Physics 2007-05-23 Allan I Solomon , Sonia G Schirmer

The model of an open Fermi-system is used for studying the interplay of intrinsic chaos and irreversible decay into open continuum channels. Two versions of the model are characterized by one-body chaos coming from disorder or by many-body…

Disordered Systems and Neural Networks · Physics 2014-03-31 S. Sorathia , F. M. Izrailev , G. L. Celardo , V. G. Zelevinsky , G. P. Berman

The constraints arising for a general set of causal relations, both classically and quantumly, are still poorly understood. As a step in exploring this question, we consider a coherently controlled superposition of "direct-cause" and…

Quantum Physics · Physics 2018-01-11 Adrien Feix , Časlav Brukner

In theories of communication, it is usually presumed that the involved parties perform actions in a fixed causal order. However, practical and fundamental reasons can induce uncertainties in the causal order. Here we show that a maximal…

Quantum Physics · Physics 2019-11-20 Ding Jia , Fabio Costa

The quantum switch describes a quantum operation in which two or more quantum channels act on a quantum system with the order of application determined by the state of an order quantum system. And by suitably choosing the state of the order…

Quantum Physics · Physics 2022-10-07 Debarshi Das , Somshubhro Bandyopadhyay

Many observers can simultaneously measure different parts of an environment of a quantum system in order to find out its state. To study this problem we generalize the formalism of conditional master equations to the multiple observer case.…

Quantum Physics · Physics 2007-05-23 J. Dziarmaga , D. A. R. Dalvit , W. H. Zurek

The standard model of quantum circuits assumes operations are applied in a fixed sequential "causal" order. In recent years, the possibility of relaxing this constraint to obtain causally indefinite computations has received significant…

Quantum Physics · Physics 2024-08-20 Alastair A. Abbott , Mehdi Mhalla , Pierre Pocreau

Lyapunov control (open-loop) is often confronted with uncertainties and errors in practical applications. In this paper, we analyze the robustness of Lyapunov control against the uncertainties and errors in quantum control systems. The…

Quantum Physics · Physics 2015-05-20 X. X. Yi , B. Cui , Chunfeng Wu , C. H. Oh

Indirect measurement can be used to read out the outcome of a quantum system without resorting to a straightforward approach, and it is the foundation of the measurement uncertainty relations that explain the incompatibility of conjugate…

Quantum Physics · Physics 2022-08-09 Ryo Mihashi , Yoshihiko Hasegawa

Controlling and understanding phenomena in coupled systems remains a significant challenge across diverse fields. This study investigates a simple globally coupled chemical system that exhibits a range of rich collective dynamics, from…

Pattern Formation and Solitons · Physics 2024-12-11 Premashis Kumar

Robust control of quantum systems is an increasingly relevant field of study amidst the second quantum revolution, but there remains a gap between taming quantum physics and robust control in its modern analytical form that culminated in…

The thermodynamic uncertainty relation posits that higher thermodynamic costs are essential for a system to function with greater precision. Recent discussions have expanded thermodynamic uncertainty relations beyond classical…

Quantum Physics · Physics 2023-12-13 Yoshihiko Hasegawa

In this work we analyze and bound the effect of modeling errors on the stabilization of pure states or subspaces for quantum stochastic evolutions. Different approaches are used for open-loop and feedback control protocols. For both, we…

Quantum Physics · Physics 2024-09-27 Weichao Liang , Kentaro Ohki , Francesco Ticozzi

We explore the extent to which two quantum oscillators can exchange their quantum states efficiently through a three-level system which can be spin levels of colored centers in solids. High transition probabilities are obtained using…

Quantum Physics · Physics 2023-05-04 Quentin Ansel , Alexei D. Chepelianskii , Jose Lages

In this Thesis we study the quantum to classical transition process in the context of quantum mechanics and quantum field theory. We shall analyze the effects that general environments, namely ohmic and non-ohmic, at zero and high…

Quantum Physics · Physics 2009-09-29 Paula I. Villar

We use the quantum Brownian model to derive the uncertainty relation for a quantum open system. We examine how the fluctuations of a quantum system evolve after it is brought in contact with a heat bath at finite temperature. We study the…

General Relativity and Quantum Cosmology · Physics 2015-06-25 B. L. Hu , Yuhong Zhang