Download or read book Description and Control of Decoherence in Quantum Bit Systems written by Henryk Peter Gregor Gutmann and published by . This book was released on 2005 with total page 163 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Control of Decoherence in Open Quantum Systems Using Feedback written by Narayan Ganesan and published by . This book was released on 2006 with total page 139 pages. Available in PDF, EPUB and Kindle. Book excerpt: Decoherence, which is caused due to the interaction of a quantum system with its environment plagues all quantum systems and leads to the loss of quantum properties that are vital for quantum computation and quantum information processing. In this work we propose a novel strategy using techniques from systems theory to completely eliminate decoherence and also provide conditions under which it can be done so. A novel construction employing an auxiliary system, the bait, which is instrumental to decoupling the system from the environment is presented. Almost all the earlier work on decoherence control employ density matrix and stochastic master equations to analyze the problem. Our approach to decoherence control involves the bilinear input affine model of quantum control system which lends itself to various techniques from classical control theory, but with non-trivial modifications to the quantum regime. The elegance of this approach yields interesting results on open loop decouplability and Decoherence Free Subspaces (DFS). Additionally, the feedback control of decoherence may be related to disturbance decoupling for classical input affine systems, which entails careful application of the methods by avoiding all the quantum mechanical pitfalls. The two concepts are contrasted and an improved theory of disturbance decoupling for general input affine systems is developed. In the process of calculating a suitable feedback the system has to be restructured due to its tensorial nature of interaction with the environment, which is unique to quantum systems. Finally the results are also shown to be superior to the ones obtained via master equations. In order to apply feedback a reliable information extraction scheme is presented that employs continuous indirect measurements with the help of a quantum probe. Finally, a methodology to synthesize feedback parameters itself is given, that technology permitting, could be implemented for practical 2-qubit systems to perform decoherence free Quantum Computing.
Download or read book Decoherence Suppression in Quantum Systems 2008 written by Mikio Nakahara and published by World Scientific. This book was released on 2010 with total page 202 pages. Available in PDF, EPUB and Kindle. Book excerpt: While innovative ideas and creative works increasingly drive economic success, the historic approach to encouraging innovation and creativity by granting property rights has come under attack by a growing number of legal theorists and technologists. In Laws of Creation, Ronald Cass and Keith Hylton take on these critics with a vigorous defense of intellectual property law. The authors look closely at the IP doctrines that have been developed over many years in patent, copyright, trademark, and trade secret law. In each area, legislatures and courts have weighed the benefits that come from preserving incentives to innovate against the costs of granting innovators a degree of control over specific markets. Over time, the authors show, a set of rules has emerged that supports wealth-creating innovation while generally avoiding overly expansive, growth-retarding licensing regimes. These rules are now under pressure from detractors who claim that changing technology undermines the case for intellectual property rights. But Cass and Hylton explain how technological advances only strengthen that case. In their view, the easier it becomes to copy innovations, the harder to detect copies and to stop copying, the greater the disincentive to invest time and money in inventions and creative works. The authors argue convincingly that intellectual property laws help create a society that is wealthier and inspires more innovation than those of alternative legal systems. Ignoring the social value of intellectual property rights and making what others create and nurture âeoefreeâe would be a costly mistake indeed.
Download or read book Quantum Computing written by National Academies of Sciences, Engineering, and Medicine and published by National Academies Press. This book was released on 2019-04-27 with total page 273 pages. Available in PDF, EPUB and Kindle. Book excerpt: Quantum mechanics, the subfield of physics that describes the behavior of very small (quantum) particles, provides the basis for a new paradigm of computing. First proposed in the 1980s as a way to improve computational modeling of quantum systems, the field of quantum computing has recently garnered significant attention due to progress in building small-scale devices. However, significant technical advances will be required before a large-scale, practical quantum computer can be achieved. Quantum Computing: Progress and Prospects provides an introduction to the field, including the unique characteristics and constraints of the technology, and assesses the feasibility and implications of creating a functional quantum computer capable of addressing real-world problems. This report considers hardware and software requirements, quantum algorithms, drivers of advances in quantum computing and quantum devices, benchmarks associated with relevant use cases, the time and resources required, and how to assess the probability of success.
Download or read book Control of Loss and Decoherence in Quantum Systems written by J. H. Eberly and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Decoherence Control and Symmetry in Quantum Computers written by Dave Morris Bacon and published by . This book was released on 2001 with total page 458 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Decoherence Entanglement and Information Protection in Complex Quantum Systems written by Vladimir M. Akulin and published by Springer Science & Business Media. This book was released on 2005-08-10 with total page 720 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a collection of articles on the contemporary status of quantum mechanics, dedicated to the fundamental issues of entanglement, decoherence, irreversibility, information processing, and control of quantum evolution, with a view of possible applications. It has multidisciplinary character and is addressed at a broad readership in physics, computer science, chemistry, and electrical engineering. It is written by the world-leading experts in pertinent fields such as quantum computing, atomic, molecular and optical physics, condensed matter physics, and statistical physics.
Download or read book Decoherence and Its Implications in Quantum Computation and Information Transfer written by Tony Gonis and published by IOS Press. This book was released on 2001 with total page 380 pages. Available in PDF, EPUB and Kindle. Book excerpt: Decoherence is the physical process by which the classical world - the world of common sense - emerges from its quantum underpinnings. This physical process refers to the loss of phase coherence between the parts of a quantum system, because of the interaction of the system with the environment.
Download or read book Quantum Computing Since Democritus written by Scott Aaronson and published by Cambridge University Press. This book was released on 2013-03-14 with total page 403 pages. Available in PDF, EPUB and Kindle. Book excerpt: Takes students and researchers on a tour through some of the deepest ideas of maths, computer science and physics.
Download or read book Classical and Quantum Information written by Dan C. Marinescu and published by Academic Press. This book was released on 2011-01-07 with total page 745 pages. Available in PDF, EPUB and Kindle. Book excerpt: A new discipline, Quantum Information Science, has emerged in the last two decades of the twentieth century at the intersection of Physics, Mathematics, and Computer Science. Quantum Information Processing is an application of Quantum Information Science which covers the transformation, storage, and transmission of quantum information; it represents a revolutionary approach to information processing. Classical and Quantum Information covers topics in quantum computing, quantum information theory, and quantum error correction, three important areas of quantum information processing. Quantum information theory and quantum error correction build on the scope, concepts, methodology, and techniques developed in the context of their close relatives, classical information theory and classical error correcting codes. - Presents recent results in quantum computing, quantum information theory, and quantum error correcting codes - Covers both classical and quantum information theory and error correcting codes - The last chapter of the book covers physical implementation of quantum information processing devices - Covers the mathematical formalism and the concepts in Quantum Mechanics critical for understanding the properties and the transformations of quantum information
Download or read book Decoherence Control and Encoding of Coupled Solid state Quantum Bits written by Markus János Storcz and published by . This book was released on 2005 with total page 254 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Characterization and Decoherence Control of Open Quantum Systems written by Masoud Mohseni and published by . This book was released on 2007 with total page 496 pages. Available in PDF, EPUB and Kindle. Book excerpt: An optimal quantum algorithm for "direct characterization of quantum dynamics" (DCQD) is introduced. The DCQD method can be utilized to completely determine the quantum dynamical superoperator acting on an open quantum system. In contrast to all other known quantum process tomography (QPT) schemes, this scheme relies on error-detection techniques and does not require any quantum state tomography. By analysis of the number of required experimental configurations and quantum operations in a given Hilbert space, it is demonstrated that this approach is more efficient than all other known QPT schemes. DCQD can be applied, by construction, to the task of partial characterization of quantum dynamics. Specifically, it is demonstrated that the DCQD algorithm can be efficiently used for Hamiltonian identification, and also for simultaneous determination of both the relaxation time T1 and dephasing time T2. Furthermore, it is argued that the DCQD scheme is experimentally implementable in a variety of prominent quantum information processing systems, and it is explicitly shown how it can be physically realized in photonic systems with present day technology. The ability of a quantum system to perform arbitrary or "universal" quantum operations is restricted to its naturally available/controllable interactions. It is shown that quantum systems with an effective exchange interaction can be made operationally universal by utilizing a subspace or a subsystem of the combined principal system and an auxiliary system. Moreover, it is demonstrated that universal fault-tolerant quantum computation can be performed on these systems without utilizing any form of single-qubit control. Characterization and control of open quantum systems are among the central and fundamental problems in quantum physics. A crucial primitive is the characterization of the dynamics of a quantum system that has an unknown interaction with its embedding environment. Another essential task is to control the decoherence of an open quantum system by using naturally available interactions. This thesis addresses the above fundamental problems in two separate parts. In the first part, a general theory for direct and complete characterization of quantum dynamics is introduced. In the second part, a scheme for performing arbitrary quantum operations on spin-based quantum systems is presented. This scheme can be implemented in the presence of environmental noise and faulty quantum operations without need to control the state of spins individually.
Download or read book Quantum Computing in Solid State and Coherent Behavior of Open Quantum Systems written by and published by . This book was released on 2003 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: We have developed and investigated models of realization of quantum computing in solid-state semiconductor heterostructures, and explored decoherence properties of relevance in evaluation of quantum-computing systems. Quantum bits (qubits) are nuclear or outer bound electron spins in donor atoms embedded in the zero-spin host material, which could be an isotope of Si. In order to accomplish control of each qubit and also have controlled qubit-qubit interactions, we consider exchange of electrons, either bound or in two-dimensional electron gas. Our emphasis has been on spin-excitons that form in the electron gas in heterostructures under quantum Hall effect conditions: at low temperatures and in high magnetic fields. Their spectral gap causes slow relaxation and decoherence, while still allowing controlled qubit-qubit interactions at qubit separations of order 100 nm. We have carried detailed many-body perturbative calculations of qubit interactions and decoherence in such systems. We have also obtained results promoting general understanding of quantum decoherence and measurement processes, within the setting appropriate for quantum computing applications.
Download or read book Performance Evaluation Methodologies and Tools written by Qianchuan Zhao and published by Springer Nature. This book was released on 2021-12-07 with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book constitutes the refereed conference proceedings of the 14th International Conference on Performance Evaluation Methodologies and Tools, VALUETOOLS 2021, held in October 2021. Due to the safety concerns and travel restrictions caused by COVID-19, VALUETOOLS took place online in a live stream. VALUETOOLS 2021 aims to provide a world-leading and multidisciplinary venue for researchers and practitioners in diverse disciplines such as computer science, networks and telecommunications, operations research, optimization, control theory and manufacturing. The 16 full papers were carefully reviewed and selected from 32 submissions and focus on methodologies and practices in modelling, performance evaluation and optimization of complex systems.
Download or read book Manipulating Quantum Systems written by National Academies of Sciences, Engineering, and Medicine and published by National Academies Press. This book was released on 2020-09-14 with total page 315 pages. Available in PDF, EPUB and Kindle. Book excerpt: The field of atomic, molecular, and optical (AMO) science underpins many technologies and continues to progress at an exciting pace for both scientific discoveries and technological innovations. AMO physics studies the fundamental building blocks of functioning matter to help advance the understanding of the universe. It is a foundational discipline within the physical sciences, relating to atoms and their constituents, to molecules, and to light at the quantum level. AMO physics combines fundamental research with practical application, coupling fundamental scientific discovery to rapidly evolving technological advances, innovation and commercialization. Due to the wide-reaching intellectual, societal, and economical impact of AMO, it is important to review recent advances and future opportunities in AMO physics. Manipulating Quantum Systems: An Assessment of Atomic, Molecular, and Optical Physics in the United States assesses opportunities in AMO science and technology over the coming decade. Key topics in this report include tools made of light; emerging phenomena from few- to many-body systems; the foundations of quantum information science and technologies; quantum dynamics in the time and frequency domains; precision and the nature of the universe, and the broader impact of AMO science.
Download or read book Thermodynamics and Control of Open Quantum Systems written by Gershon Kurizki and published by Cambridge University Press. This book was released on 2022-01-13 with total page 487 pages. Available in PDF, EPUB and Kindle. Book excerpt: The theory of open quantum systems is developed from first principles, and a detailed discussion of real quantum devices is also covered. This unique and self-contained book is accessible to graduate students and researchers working in atomic physics, quantum information, condensed matter physics, and quantum chemistry.
Download or read book Irreversible Quantum Dynamics written by Fabio Benatti and published by Springer. This book was released on 2008-01-11 with total page 362 pages. Available in PDF, EPUB and Kindle. Book excerpt: The idea of editing the present volume in the Lecture Notes in Physics series arosewhileorganizingthe“ConferenceonIrreversibleQuantumDynamics”that took place at The Abdus Salam International Center for Theoretical Physics, Trieste, Italy, from July 29 to August 2, 2002. The aim of the Conference was to bring together di?erent groups of - searcherswhoseinterestsandpursuitsinvolveirreversibilityandtimeasymmetry in quantum mechanics. The Conference promoted open and in-depth exchanges of di?erent points of view, concerning both the content and character of qu- tum irreversibility and the methodologies used to study it. The following main themes were addressed: • Theoretical Aspects of Quantum Irreversible Dynamics • Open Quantum Systems and Applications • Foundational Aspects of Irreversible Quantum Dynamics • Asymmetric Time Evolution and Resonances Eachthemewasreviewedbyanexpertinthe?eld,accompaniedbymorespeci?c, research-like shorter talks. The whole topic of quantum irreversibility in all its manifold aspects has always raised a lot of interest, starting with the description of unstable systems in quantum mechanics and the issue of quantum measurement. Further, in - cent years a boost of activity concerning noise, dissipation and open systems has been prompted by the fast developing ?eld of quantum communication and information theory. These considerations motivated the editors to put together a volume that tries to summarize the present day status of the research in the ?eld, with the aim of providing the reader with an accessible and exhaustive introduction to it.
