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Related papers: Decoherence-free linear quantum subsystems

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The modeling of nonlinear dynamics based on Koopman operator theory, which is originally applicable only to autonomous systems with no control, is extended to non-autonomous control system without approximation to input matrix B. Prevailing…

Systems and Control · Electrical Eng. & Systems 2024-08-23 H. Harry Asada , Jose A. Solano-Castellanos

This is a review paper concerned with the global consistency of the quantum dynamics of non-commutative systems. Our point of departure is the theory of constrained systems, since it provides a unified description of the classical and…

High Energy Physics - Theory · Physics 2015-05-13 F. S. Bemfica , H. O. Girotti

Basing on the theory of Feynman's influence functional and its hierarchical equations of motion, we develop a linear response theory for quantum open systems. Our theory provides an effective way to calculate dynamical observables of a…

Mesoscale and Nanoscale Physics · Physics 2011-08-31 J. H. Wei , YiJing Yan

Quantum feedback is assuming increasingly important role in quantum control and quantum information processing. In this work we analyze the application of such feedback techniques in eliminating decoherence in open quantum systems. In order…

Quantum Physics · Physics 2016-11-15 Narayan Ganesan , Tzyh Jong Tarn

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

Over the past decade we have seen an explosion of demonstrations of quantum coherence in atomic, optical, and condensed matter systems. These developments have placed a new emphasis on the production of robust and optimal quantum control…

Quantum Physics · Physics 2015-05-20 M. J. Biercuk , A. C. Doherty , H. Uys

We derive quantum kinetic equations for fermions in a homogeneous time-dependent background in presence of decohering collisions, by use of the Schwinger-Keldysh CTP-formalism. The quantum coherence (between particles and antiparticles) is…

High Energy Physics - Phenomenology · Physics 2009-03-24 Matti Herranen , Kimmo Kainulainen , Pyry Matti Rahkila

We give an explicit construction for a quantum observer coherently mimicking the dynamics of a cavity mode system and without any disturbance of the system's dynamics. This gives the exact analogue of the Luenberger observer used in…

Quantum Physics · Physics 2016-09-22 John E. Gough , Nina H. Amini

The vast majority of the literature dealing with quantum dynamics is concerned with linear evolution of the wave function or the density matrix. A complete dynamical description requires a full understanding of the evolution of measured…

The processes of radiation damping and decoherence in Quantum Electrodynamics are studied from an open system's point of view. Employing functional techniques of field theory, the degrees of freedom of the radiation field are eliminated to…

Quantum Physics · Physics 2007-05-23 Heinz-Peter Breuer , Francesco Petruccione

The equilibrium properties of an open harmonic oscillator are considered in three steps: First the creation and destruction operators are generalized for open dynamics and the creation operator is used to construct coherent states. The…

Quantum Physics · Physics 2020-06-24 Janos Polonyi

It has been experimentally demonstrated that quantum coherence can persist in macroscopic phenomena [J.R. Friedman et al.,Nature, 406 (2000) 43]. To face the challenge of this new fact, in this article QM in its standard form is assumed to…

Quantum Physics · Physics 2007-05-23 F. Herbut

We analyze the control by electromagnetic fields of quantum systems with infinite dimensional Hilbert space and a discrete spectrum. Based on recent mathematical results, we rigorously show under which conditions such a system can be…

Optimization and Control · Mathematics 2014-12-15 Elie Assémat , Thomas Chambrion , Dominique Sugny

We study quantum decoherence numerically in a system consisting of a relativistic quantum field theory coupled to a measuring device that is itself coupled to an environment. The measuring device and environment are treated as quantum,…

Quantum Physics · Physics 2020-10-13 Chris Nagele , Oliver Janssen , Matthew Kleban

Efficacious quantum information processing relies on extended coherence and precise control. Investigating the limitations surrounding quantum processors is vital for their advancement. In their operation, one challenge is inadvertent wave…

Quantum Physics · Physics 2024-05-14 Alfred Li , Herschel A. Rabitz , Benjamin Lienhard

A basic linearity of quantum dynamics, that density matrices are mapped linearly to density matrices, is proved very simply for a system that does not interact with anything else. It is assumed that at each time the physical quantities and…

Quantum Physics · Physics 2009-11-11 Thomas F. Jordan

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

Physical systems in real life are inextricably linked to their surroundings and never completely separated from them. Truly closed systems do not exist. The phenomenon of decoherence, which is brought about by the interaction with the…

High Energy Physics - Phenomenology · Physics 2024-07-11 Gabriela Barenboim , Alberto M. Gago

This paper studies quantum limits to dynamical sensors in the presence of decoherence. A modified purification approach is used to obtain tighter quantum detection and estimation error bounds for optical phase sensing and optomechanical…

Quantum Physics · Physics 2013-07-04 Mankei Tsang

The decoherence induced on a single qubit by its interaction with the environment is studied. The environment is modelled as a scalar two-level boson system that can go through either first order or continuous excited state quantum phase…

Quantum Physics · Physics 2015-05-14 P. Perez-Fernandez , A. Relano , J. M. Arias , J. Dukelsky , J. E. Garcia-Ramos