Download or read book Non Markovian Dynamics of Open Quantum Systems written by Christen Herbert Fleming and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Non Markovian Dynamics of Open Quantum Systems written by Carole Addis and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Non Markovian Dynamics of Open Quantum Systems in Structured Environments written by Adam Burgess and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This note is part of Quality testing.
Download or read book Control of Open Quantum Systems Examples Methods for Non markovian Dynamics written by Jonas Fischer and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Open Quantum Systems written by Ángel Rivas and published by Springer Science & Business Media. This book was released on 2011-10-01 with total page 103 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this volume the fundamental theory of open quantum systems is revised in the light of modern developments in the field. A unified approach to the quantum evolution of open systems is presented by merging concepts and methods traditionally employed by different communities, such as quantum optics, condensed matter, chemical physics and mathematical physics. The mathematical structure and the general properties of the dynamical maps underlying open system dynamics are explained in detail. The microscopic derivation of dynamical equations, including both Markovian and non-Markovian evolutions, is also discussed. Because of the step-by-step explanations, this work is a useful reference to novices in this field. However, experienced researches can also benefit from the presentation of recent results.
Download or read book Control of Open Quantum System written by Jonas Fischer and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Usually open quantum systems are considered to be under the influence of noise and therefore faulty. On the other hand, a controlled system is regarded as something stable and predictable. It is often neglected, that the two aspects are very closely related. A perfectly isolated quantum system will not be subject to environmental influences, but this makes it also impossible to interact with it in any manner. Controlling and measuring such a system is impossible and therefore of no technical relevance.Every system used in any technological device therefore must be in contact with its environment. The question, which is the starting point of this thesis is whether it is possible to not only control a system despite of its contact to some environment, but whether there are cases, where this interaction can be necessary, or at least helpful for certain control tasks.The first part of the thesis focuses on such a task, namely the purification of a qubit. Here the environment is essential, in order to serve as an entropy sink. The simplicity of the chosen model allowed us to derive the necessary time for the purification process analytically for arbitrary controls and interactions. This is helpful for architectures, where implementations of various configurations is possible.The second half of the thesis covers more methodogical work. In the example of the qubit reset, we see that the necessary time to perform the task is determined by the coupling between the system and environment. In order to perform such tasks fast, we have to develop a framework, which allows to analyse systems beyond the usual weak-coupling limit. There exists so far no general method for the propagation of such systems, which also allows for thermalisation. The surrogate Hamiltonian method is a promising candidate to capture dynamics beyond the weak-coupling limit and its extension, the stochastic surrogate Hamiltonian, allows for thermalisation. We expand the stochastic surrogate Hamiltonian by introducing a new method of performing stochastic swaps. This method is then tested on a simple example model.
Download or read book Modelling Non Markovian Quantum Systems Using Tensor Networks written by Aidan Strathearn and published by Springer Nature. This book was released on 2020-08-31 with total page 113 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents a revolutionary technique for modelling the dynamics of a quantum system that is strongly coupled to its immediate environment. This is a challenging but timely problem. In particular it is relevant for modelling decoherence in devices such as quantum information processors, and how quantum information moves between spatially separated parts of a quantum system. The key feature of this work is a novel way to represent the dynamics of general open quantum systems as tensor networks, a result which has connections with the Feynman operator calculus and process tensor approaches to quantum mechanics. The tensor network methodology developed here has proven to be extremely powerful: For many situations it may be the most efficient way of calculating open quantum dynamics. This work is abounds with new ideas and invention, and is likely to have a very significant impact on future generations of physicists.
Download or read book Impact of Von Neumann Conditions on Non Markovian Dynamics of Open Quantum Systems written by Paul Kocian and published by . This book was released on 2006 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dynamics of Open Quantum Systems Embedded in a Non Markovian Environment written by Jie Xu and published by . This book was released on 2014 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Open Quantum Systems written by Subhashish Banerjee and published by Springer. This book was released on 2018-11-01 with total page 278 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book discusses the elementary ideas and tools needed for open quantum systems in a comprehensive manner. The emphasis is given to both the traditional master equation as well as the functional (path) integral approaches. It discusses the basic paradigm of open systems, the harmonic oscillator and the two-level system in detail. The traditional topics of dissipation and tunneling, as well as the modern field of quantum information, find a prominent place in the book. Assuming a basic background of quantum and statistical mechanics, this book will help readers familiarize with the basic tools of open quantum systems. Open quantum systems is the study of quantum dynamics of the system of interest, taking into account the effects of the ambient environment. It is ubiquitous in the sense that any system could be envisaged to be surrounded by its environment which could naturally exert its influence on it. Open quantum systems allows for a systematic understanding of irreversible processes such as decoherence and dissipation, of the essence in order to have a correct understanding of realistic quantum dynamics and also for possible implementations. This would be essential for a possible development of quantum technologies.
Download or read book The Theory of Open Quantum Systems written by Heinz-Peter Breuer and published by Oxford University Press, USA. This book was released on 2002 with total page 648 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book treats the central physical concepts and mathematical techniques used to investigate the dynamics of open quantum systems. To provide a self-contained presentation the text begins with a survey of classical probability theory and with an introduction into the foundations of quantum mechanics with particular emphasis on its statistical interpretation. The fundamentals of density matrix theory, quantum Markov processes and dynamical semigroups are developed. The most important master equations used in quantum optics and in the theory of quantum Brownian motion are applied to the study of many examples. Special attention is paid to the theory of environment induced decoherence, its role in the dynamical description of the measurement process and to the experimental observation of decohering Schrodinger cat states. The book includes the modern formulation of open quantum systems in terms of stochastic processes in Hilbert space. Stochastic wave function methods and Monte Carlo algorithms are designed and applied to important examples from quantum optics and atomic physics, such as Levy statistics in the laser cooling of atoms, and the damped Jaynes-Cummings model. The basic features of the non-Markovian quantum behaviour of open systems are examined on the basis of projection operator techniques. In addition, the book expounds the relativistic theory of quantum measurements and discusses several examples from a unified perspective, e.g. non-local measurements and quantum teleportation. Influence functional and super-operator techniques are employed to study the density matrix theory in quantum electrodynamics and applications to the destruction of quantum coherence are presented. The text addresses graduate students and lecturers in physics and applied mathematics, as well as researchers with interests in fundamental questions in quantum mechanics and its applications. Many analytical methods and computer simulation techniques are developed and illustrated with the help of numerous specific examples. Only a basic understanding of quantum mechanics and of elementary concepts of probability theory is assumed.
Download or read book Investigating Non Markovian Dynamics of Quantum Open Systems written by Yusui Chen and published by . This book was released on 2015 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Non Markovian Open Quantum Systems written by Maike Gail Zinterl and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We examine different nonlinear open quantum systems and calculate the non-Markovianity based on the distinguishability between two density matrices. We show that for a single spin (qubit) coupled to a bosonic field the non-Markovianity depends on the spectral density function and can take on any number N with 0 ≤ N ≤ 1, meaning the dynamics can be Markovian or highly non-Markovian. For the main result we consider a system of Ntot identical spins coupled to an environment in the mean-field way. Each spin is coupled to a local and the common reservoir. There are only indirect interactions between the spins through the common reservoir. In limit Ntot → 1 the subsystem consisting of a fixed set of n particles reduces to a factorized state in which each factor is a single spin evolving according to a nonlinear Hartree-Lindblad equation which is exactly solvable. For non-stationary initial spin states the non-Markovianity diverges. In this instance we can never approximate the dynamics of the quantum system by a Markovian master equation and this implies that in the mean field models, memory effects are significant.
Download or read book Non Markovian Effects in Open Quantum Systems written by Jens Eckel and published by . This book was released on 2009 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Studying the Dynamics of Open Quantum Systems Using Photons written by Daniel Fernando Urrego González and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We experimentally present the controlled transition, of an open-quantum system, between Markovian and Non-Markovian dynamics. The polarization of light is used as the system, whereas the environment is represented by the spatial structure of light. The controlled coupling of theses two domains is done by a polarization sensitive tunable beam displacer. Additionally, We present the experimental implementation and theoretical model of a controllable dephasing quantum channel using the same photonic variables. Differently, from standard dephasing channels, the channel here reported presents an exotic behavior, in the sense that the evolution of a state, from a pure to a mixed state, shows an oscillatory behavior if tracked in the Bloch sphere.
Download or read book The Theory of Non Markovian Open Quantum Systems written by Cesar Alberto Rodriguez and published by . This book was released on 2008 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt: We study the role of correlations with the environment as the source of non-Markovian quantum evolutions. We first focus on the impact that correlations with the environment can have on the dynamical map that evolve the system. We expand the set of initial states of a system and its environment that are known to guarantee completely positive reduced dynamics for the system when the combined state evolves unitarily. We characterize the correlations in the initial state in terms of its quantum discord. The induced maps can be not completely positive when quantum correlations including, but not limited to, entanglement are present. We discuss the implications and limitations of the Markov approximation necessary to derive the Kossakowski-Lindblad master equation. A generalized non-Markovian master equation is derived from the dynamical map of systems correlated with their environment. The physical meaning of not completely positive maps is studied to obtain a consistent theory of non-Markovian quantum dynamics. These are associated to inverse maps necessary to establish correlations and they give rise to a canonical embedding map that is local in time. This master equation goes beyond the Kossakowski-Lindblad master equation. Non-equilibrium quantum thermodynamics can be be studied within this theory. Through out this discussion, the general dynamics of two interacting qubits is used as an example for illustrations.
Download or read book Open Quantum Systems with Time delayed Interactions written by Simon Whalen and published by . This book was released on 2015 with total page 129 pages. Available in PDF, EPUB and Kindle. Book excerpt: The subject of this thesis is the modelling of non-Markovian open quantum systems, in particular those that display memory effects due to time-delayed interactions. I study these systems in the context of a model of an open quantum system that interacts with a bosonic environment by way of particle exchanges. While the model is flexible enough to describe quite general memory effects, this work focuses to a large extent on a single prototypical system. This system emits into a coherent feedback loop with a time delay, and it captures the essential phenomena we aim to model. Within the context of this general model, I develop a general approach to spontaneous emission from singly-excited systems and show how to calculate the corresponding emission spectra. I also evaluate two commonly-used perturbative techniques in the context of spontaneous emission from singly-excited systems, coming to the conclusion that perturbation theory is of limited use in modelling open quantum systems with delayed feedback. I then turn attention to exact equations of motion for more general non-Markovian open quantum systems. I derive Heisenberg-Langevin equations that describe a large class of such systems, and solve these equations analytically for a series of simple bosonic systems. I also use the theory of cascaded open quantum systems to simulate systems with delayed coherent feedback in the limit of long time delay, and compare the results of these simulations with the analytic solutions obtained in the Heisenberg picture. Finally, I show that once we have a solution to a given Heisenberg-Langevin equation we can derive an alternative, time-local equation of motion that describes equivalent dynamics, and that these time-local Heisenberg-Langevin equations can in turn be used to derive corresponding time-local master equations. These master equations provide an exact description of the non-Markovian dynamics, but this treatment is limited to linear, bosonic systems-those systems for which the Heisenberg-Langevin equations can be solved in closed form. I discuss the prospect of generalising these master equations to take into account nonlinear and fermionic systems.
