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Related papers: Quantum control by the environment: Turing uncompu…

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Novel concepts, perspectives and challenges in measuring and controlling an open quantum system via sequential schemes are shown. We discuss how similar protocols, relying both on repeated quantum measurements and dynamical decoupling…

Quantum Physics · Physics 2019-06-26 Stefano Gherardini , Andrea Smirne , Matthias M. Müller , Filippo Caruso

Invariant-based inverse engineering is an elegant approach to quantum control with corresponding experimental implementations that perform tasks with applications in quantum information processing such as shuttling trapped ions. We build on…

Quantum Physics · Physics 2021-12-30 Selwyn Simsek , Florian Mintert

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

Different approaches in quantifying environmentally-induced decoherence are considered. We identify a measure of decoherence, derived from the density matrix of the system of interest, that quantifies the environmentally induced error,…

Mesoscale and Nanoscale Physics · Physics 2010-10-12 Arkady Fedorov , Leonid Fedichkin , Vladimir Privman

Quantum controls realize the unitary or nonunitary operations employed in quantum computers, quantum simulators, quantum communications, and other quantum information devices. They implement the desired quantum dynamics with the help of…

Quantum Physics · Physics 2022-06-02 T S Mahesh , Priya Batra , M. Harshanth Ram

We use contemporary quantum computers to experimentally investigate quantum steering ofan open quantum system by measurements on its environment. On three IBMQ processors wedistinguish a qubit as the open system and perform pairwise…

Quantum Physics · Physics 2023-03-28 Lennart Maximilian Seifert , Konstantin Beyer , Kimmo Luoma , Walter T. Strunz

In a quantum processor, the device design and external controls together contribute to the quality of the target quantum operations. As we continuously seek better alternative qubit platforms, we explore the increasingly large device and…

Quantum Physics · Physics 2023-12-08 Xiaotong Ni , Hui-Hai Zhao , Lei Wang , Feng Wu , Jianxin Chen

When confined to small regions quantum systems exhibit electronic and structural properties different from their free space behavior. These properties are of interest, for example, for molecular insertion, hydrogen storage and the…

Quantum Physics · Physics 2018-04-30 R. Vilela Mendes

Many promising ideas for quantum computing demand the experimental ability to directly switch 'on' and 'off' a physical coupling between the component qubits. This is typically the key difficulty in implementation, and precludes quantum…

Quantum Physics · Physics 2009-11-07 Simon C. Benjamin , Sougato Bose

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

Quantum sensing is commonly described as a constrained optimization problem: maximize the information gained about an unknown quantity using a limited number of particles. Important sensors including gravitational-wave interferometers and…

Quantum Physics · Physics 2020-08-05 Morgan W. Mitchell

Quantum coherence inherently affects the dynamics and the performances of a quantum machine. Coherent control can, at least in principle, enhance the work extraction and boost the velocity of evolution in an open quantum system. Using…

Quantum Physics · Physics 2018-12-10 Vasco Cavina , Andrea Mari , Alberto Carlini , Vittorio Giovannetti

The superposition of causal order shows promise in various quantum technologies. However, the fragility of quantum systems arising from environmental interactions, leading to dissipative behavior and irreversibility, demands a deeper…

The importance of feedback control is being increasingly appreciated in quantum physics and applications. This paper describes the use of optimal control methods in the design of quantum feedback control systems, and in particular the paper…

Quantum Physics · Physics 2009-11-10 M. R. James

To observe or control a quantum system, one must interact with it via an interface. This letter exhibits simple universal quantum interfaces--quantum input/output ports consisting of a single two-state system or quantum bit that interacts…

Quantum Physics · Physics 2007-05-23 Seth Lloyd , Andrew J. Landahl , Jean-Jacques E. Slotine

Developments in the foundations of quantum mechanics have identified several attributes and tests associated with the "quantumness" of systems, including entanglement, nonlocality, quantum erasure, Bell test, etc. Here we introduce and…

Quantum Physics · Physics 2016-05-03 Torsten Scholak , Paul Brumer

This article considers some control problems for closed and open two-level quantum systems. The closed system's dynamics is governed by the Schr\"odinger equation with coherent control. The open system's dynamics is governed by the…

Quantum Physics · Physics 2023-12-01 Oleg V. Morzhin , Alexander N. Pechen

Towards the full-fledged quantum computing, what do we need? Obviously, the first thing we need is a (many-body) quantum system, which is reasonably isolated from its environment in order to reduce the unwanted effect of noise, and the…

Quantum Physics · Physics 2017-01-03 Koji Maruyama , Daniel Burgarth

To implement quantum information technologies, carefully designed control for preparing a desired state plays a key role. However, in realistic situation, the actual performance of those methodologies is severely limited by decoherence.…

Quantum Physics · Physics 2025-10-02 Kohei Kobayashi

We prove upper and lower bounds relating the quantum gate complexity of a unitary operation, U, to the optimal control cost associated to the synthesis of U. These bounds apply for any optimal control problem, and can be used to show that…

Quantum Physics · Physics 2009-11-13 Michael A. Nielsen , Mark R. Dowling , Mile Gu , Andrew C. Doherty