Download or read book Non markovian Dynamical Processes of Open Quantum Systems Studies on Entanglement Transport Properties and Correlation Functions written by 陳柏文 and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Non linear Cooperative Effects in Open Quantum Systems written by Nicolae A. Enaki and published by . This book was released on 2016 with total page 344 pages. Available in PDF, EPUB and Kindle. Book excerpt: This monograph, Non-linear Cooperative Effects in Open Quantum Systems: Entanglement and Second Order Coherence is dedicated to the large auditory of specialists interested in the modern approaches in quantum open systems, cooperative phenomena between excited atoms and the field of the non-linear interaction. Special attention is dedicated to the problems of non-linear interaction with vacuum fields and thermostat with finite temperature, but quantum aspects of laser generation of light in non-linear interaction with finite numbers of cavity modes remain the center of attention. In many situations, the limit to the traditional cooperative phenomena of open quantum systems and thermodynamics are taken into consideration. As the book contains the class of non-linear effects of generations of the particle in such cooperative phenomena, the author's aim was to describe squeezed problems and affect entanglement between the generation photons and phonons in cooperative processes. The new phenomenon of cooperative emission in the single- and two-quantum processes are carefully described for large audiences of specialists in the field of quantum optics and condensed matter physics, chemistry and biology.

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 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 Frontiers In Quantum Information Research Proceedings Of The Summer School On Decoherence Entanglement Entropy And Proceedings Of The Workshop On Mps Dmrg written by Mikio Nakahara and published by World Scientific. This book was released on 2012-06-08 with total page 359 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a collection of lecture notes/contributions from a summer school on decoherence, entanglement & entropy and a workshop on MPS (matrix product states) & DMRG (density matrix renormalization group). Subjects of the summer school include introduction to MPS, black holes, qubits and octonions, weak measurement, entanglement measures and separability, generalized Bell inequalities, among others. Subjects of the workshop are dedicated to MPS and DMRG. Applications to strongly correlated systems and integrable systems are also mentioned. Contributions to this book are prepared in a self-contained manner so that a reader with a modest background in quantum information and quantum computing may understand the subjects.

Download or read book Novel Transport in Quantum Phases and Entanglement Dynamics Beyond Equilibrium written by Joseph C. Szabo and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Understanding and identifying quantum phases have been longstanding pursuits in the field condensed matter physics. The most exciting modern problems lie at the intersection of strong correlations and quantum information where highly entangled phases of matter are the most difficult to solve both analytically and computationally. The overarching aim of this thesis is to advance our understanding of strongly correlated materials in light of advanced, microscopic measurement techniques, capable of imaging and manipulating single qubits and measuring fascinating physics such as quantum entanglement. We begin our study with the Fermi-Hubbard model, a theoretical model that captures the insulating and conducting phases of high-temperature superconducting materials, and we end our discussion by characterizing novel quantum phases and dynamics realized on cutting-edge quantum simulation platforms. Our first focus is on the repulsive Fermi-Hubbard model. We elucidate the mechanism by which a Mott insulator transforms into a non-Fermi liquid metal upon increasing disorder at half filling. By correlating maps of the local density of states, the local magnetization, and the local bond conductivity, we find a collapse of the Mott gap toward a V-shape pseudogapped density of states that occurs concomitantly with the decrease of magnetism around the highly disordered sites, while the electronic bond conductivity increases. We propose that these metallic regions percolate to form an emergent non-Fermi liquid phase with a conductivity that increases with temperature. Our results provide one of the first microscopic investigations of dynamical response and how these two phases (correlated metal and Mott insulator) coexist microscopically and lead to an overall macroscopic phase transition. Our work provides novel predictions for electron conductivity measured via local microwave impedance combined with charge and spin local spectroscopies. Expanding beyond the ground state properties of interacting matter, revolutionary quantum simulation experiments provide access to new regimes of quantum matter such as dynamical transitions and steady states in nonequilibrium conditions. This allows us to explore the most mind-boggling properties of interacting quantum systems: entanglement. In our first venture exploring the field of nonequilibrium quantum dynamics, we bridge foundational atomic, molecular, and optical (AMO) and condensed matter models. We investigate competing entanglement dynamics in an Ising-spin chain coupled to an external central ancilla qudit. In studying the real-time behavior following a quench from an unentangled spin-ancilla state, we find that the ancilla entanglement entropy tracks the dynamical phase transition in the underlying spin system. In this composite setting, purely spin-spin entanglement metrics such as mutual information and quantum Fisher information (QFI) decay as the ancilla entanglement entropy grows. We define multipartite entanglement loss (MEL) as the difference between collective magnetic fluctuations and QFI, which is zero in the pure spin chain limit. MEL directly quantifies the ancilla's effect on the development of spin-spin entanglement. One of our central results is that we find MEL is proportional to the exponential of entanglement entropy in real-time. Our results provide a platform for exploring composite system entanglement dynamics and suggest that MEL serves as a quantitative estimate of information entropy shared between collective spins and the ancilla qudit. Our results present a new framework that connects physical spin-fluctuations, QFI, and bipartite entanglement entropy between collective quantum systems. We reduce the qudit/bosonic environment to a single (central) qubit as to investigate the scrambling capacity added by a simple c-qubit. We present the novel ring-star Ising model as a bridge between fast-slow scrambling: a locally interacting spin-1/2 system uniformly coupled to a central qubit vertex. Each spin becomes next-nearest neighbor to all others through the c-qubit, where stronger central coupling continuously degrades any sense of locality and achieves effective all-to-all interactions. Meanwhile, the central qubit adds two level structure to all previous eigenstates in the spectrum. We study operator and entanglement dynamics in a nonintegrable ring-star, spin-1/2 Ising model with tunable central spin coupling. As the interaction with the c-spin increases across all sites, we find a surprising transition from super-ballistic scrambling and information growth to continuously restricted sub-ballistic entanglement and increasingly inhibited operator growth. This slow growth occurs on intermediate timescales that extend exponentially with increasing coupling, indicative of logarithmic entanglement growth. We provide exact dynamics of small systems working with non-equilibrium, effective infinite temperature states, and additionally contribute analytic early-time expansions that support the observed rapid scrambling to quantum Zeno-like crossover. Finally, we apply the properties of entanglement to highlight numerically approximate methods for simulating quantum and semiclassical systems. When entanglement slowly develops locally, tensor network methods allow for efficient simulation of the minimal Hilbert space required to store the quantum wavefunction evolving under Schrodinger dynamics or quantum operators under Heisenberg evolution. In the limit of long-range interactions, the system is increasingly semiclassical where the wavefunction spreads rapidly, but the full quantum Hilbert space approaches proximate conservation of collective observables. Here we review tensor network and semiclassical numerical algorithms and provide a brief discussion on applying them to simulate the quench dynamics of the Heisenberg model. We highlight the regimes where we expect them to be accurate and the intermediate regions where the two become approximate from different limits on the range of interaction.

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 Non Markovian Effects Decoherence Processes in Open Quantum Systems written by Graeme Pleasance and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Potentiality Entanglement and Passion at a Distance written by Robert S. Cohen and published by Springer Science & Business Media. This book was released on 2013-03-14 with total page 275 pages. Available in PDF, EPUB and Kindle. Book excerpt: Potentiality, Entanglement and Passion-at-a-Distance is a book for theoretical physicists and philosophers of modern physics. It treats a puzzling and provocative aspect of recent quantum physics: the apparent interaction of certain physical events that cannot share any causal connection. These are said to be `entangled' in some way, but an explanation remains elusive. Abner Shimony - to whom the book is dedicated - and others suggest the need to revive the category of what may be seen as a metaphysical potentiality. Abner has described these events without actions to link them as `passion at a distance': not active, but passive. The discussions gathered here are written by a truly remarkable cast of scientists and philosophers and shed new light on the most profound puzzles of our times.

Download or read book Quantum Dynamical Semigroups and Applications written by Robert Alicki and published by Springer Science & Business Media. This book was released on 2007-04-23 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reinvigorated by advances and insights the quantum theory of irreversible processes has recently attracted growing attention. This volume introduces the very basic concepts of semigroup dynamics of open quantum systems and reviews a variety of modern applications. Originally published as Volume 286 (1987) in Lecture in Physics, this volume has been newly typeset, revised and corrected and also expanded to include a review on recent developments.

Download or read book Quantum Entanglement of Complex Structures of Photons written by Robert Fickler and published by Springer. This book was released on 2015-09-08 with total page 115 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis casts new light on quantum entanglement of photons with complex spatial patterns due to direct coincidence imaging. It demonstrates novel methods to generate, investigate, and verify entanglement of complex spatial structures. Quantum theory is one of the most successful and astonishing physical theories. It made possible various technical devices like lasers or mobile phones and, at the same time, it completely changed our understanding of the world. Interestingly, such counterintuitive features like entanglement are an important building block for future quantum technologies. In photonic experiments, the transverse spatial degree of freedom offers great potential to explore fascinating phenomena of single photons and quantum entanglement. It was possible to verify the entanglement of two photons with very high quanta of orbital angular momentum, a property of photons connected to their spatial structure and theoretically unbounded. In addition, modern imaging technology was used to visualize the effect of entanglement even in real-time and to show a surprising property: photons with complex spatial patterns can be both entangled and not entangled in polarization depending on their transverse spatial position.

Download or read book Quantum Transport in Mesoscopic Systems written by David Sánchez and published by MDPI. This book was released on 2021-01-06 with total page 426 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mesoscopic physics deals with systems larger than single atoms but small enough to retain their quantum properties. The possibility to create and manipulate conductors of the nanometer scale has given birth to a set of phenomena that have revolutionized physics: quantum Hall effects, persistent currents, weak localization, Coulomb blockade, etc. This Special Issue tackles the latest developments in the field. Contributors discuss time-dependent transport, quantum pumping, nanoscale heat engines and motors, molecular junctions, electron–electron correlations in confined systems, quantum thermo-electrics and current fluctuations. The works included herein represent an up-to-date account of exciting research with a broad impact in both fundamental and applied topics.

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 NON EQUILIBRIUM DYNAMICS OF MANY BODY QUANTUM SYSTEMS written by and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Rapid progress in nanotechnology and naofabrication techniques has ushered in a new era of quantum transport experiments. This has in turn heightened the interest in theoretical understanding of nonequilibrium dynamics of strongly correlated quantum systems. This project has advanced the frontiers of understanding in this area along several fronts. For example, we showed that under certain conditions, quantum impurities out of equilibrium can be reformulated in terms of an effective equilibrium theory; this makes it possible to use the gamut of tools available for quantum systems in equilibrium. On a different front, we demonstrated that the elastic power of a transmitted microwave photon in circuit QED systems can exhibit a many-body Kondo resonance. We also showed that under many circumstances, bipartite fluctuations of particle number provide an effective tool for studying many-body physics--particularly the entanglement properties of a many-body system. This implies that it should be possible to measure many-body entanglement in relatively simple and tractable quantum systems. In addition, we studied charge relaxation in quantum RC circuits with a large number of conducting channels, and elucidated its relation to Kondo models in various regimes. We also extended our earlier work on the dynamics of driven and dissipative quantum spin-boson impurity systems, deriving a new formalism that makes it possible to compute the full spin density matrix and spin-spin correlation functions beyond the weak coupling limit. Finally, we provided a comprehensive analysis of the nonequilibrium transport near a quantum phase transition in the case of a spinless dissipative resonant-level model. This project supported the research of two Ph. D. students and two postdoctoral researchers, whose training will allow them to further advance the field in coming years.