Download or read book Theory of Quantum Control of Spin photon Dynamics and Spin Decoherence in Semiconductors written by Wang Yao and published by . This book was released on 2006 with total page 135 pages. Available in PDF, EPUB and Kindle. Book excerpt: Single electron spin in a semiconductor quantum dot (QD) and single photon wavepacket propagating in an optical waveguide are investigated as carriers of quantum bit (qubit) for information processing. Cavity quantum electrodynamics of the coupled system composed of charged QD, microcavity and waveguide provides a quantum interface for the interplay of stationary spin qubits and flying photon qubits via cavity assisted optical control. This interface forms the basis for a wide range of essential functions of a quantum network, including transferring, swapping, and entangling qubits at distributed quantum nodes as well as a deterministic source and an efficient detector of a single photon wavepacket with arbitrarily specified shape. The cavity assisted optical process also made possible ultrafast initialization and QND readout of the spin qubit in QD. In addition, the strong optical nonlinearity of dot-cavity-waveguide coupled system enables phase gate and entanglement operation for flying single photon qubits in waveguides. The coherence of the electron spin is the wellspring of these quantum applications being investigated. At low temperature and strong magnetic field, the dominant cause of electron spin decoherence is the coupling with the interacting lattice nuclear spins. We present a quantum solution to the coupled dynamics of the electron with the nuclear spin bath. The decoherence is treated in terms of quantum entanglement of the electron with the nuclear pair-flip excitations driven by the various nuclear interactions. A novel nuclear interaction, mediated by virtue spin-flips of the single electron, plays an important role in single spin free-induction decay (FID). The spin echo not only refocuses the dephasing by inhomogeneous broadening in ensemble dynamics but also eliminates the decoherence by electron-mediated nuclear interaction. Thus, the decoherence times for single spin FID and ensemble spin echo are significantly different. The quantum theory of decoherence also leads to a method of coherence recovery of the electron by disentanglement, realized through maneuvering the nuclear bath evolution by control of the electron spin-flip. The studies form the basis to outline the construction of a solid-state quantum network for scalable and distributed processing of quantum information.
Download or read book Towards Solid State Quantum Repeaters written by Kristiaan De Greve and published by Springer Science & Business Media. This book was released on 2013-04-16 with total page 159 pages. Available in PDF, EPUB and Kindle. Book excerpt: Towards Solid-State Quantum Repeaters: Ultrafast, Coherent Optical Control and Spin-Photon Entanglement in Charged InAs Quantum Dots summarizes several state-of-the-art coherent spin manipulation experiments in III-V quantum dots. Both high-fidelity optical manipulation, decoherence due to nuclear spins and the spin coherence extraction are discussed, as is the generation of entanglement between a single spin qubit and a photonic qubit. The experimental results are analyzed and discussed in the context of future quantum technologies, such as quantum repeaters. Single spins in optically active semiconductor host materials have emerged as leading candidates for quantum information processing (QIP). The quantum nature of the spin allows for encoding of stationary, memory quantum bits (qubits), and the relatively weak interaction with the host material preserves the spin coherence. On the other hand, optically active host materials permit direct interfacing with light, which can be used for all-optical qubit manipulation, and for efficiently mapping matter qubits into photonic qubits that are suited for long-distance quantum communication.
Download or read book Semiconductor Spintronics and Quantum Computation written by D.D. Awschalom and published by Springer Science & Business Media. This book was released on 2013-04-17 with total page 321 pages. Available in PDF, EPUB and Kindle. Book excerpt: The past few decades of research and development in solid-state semicon ductor physics and electronics have witnessed a rapid growth in the drive to exploit quantum mechanics in the design and function of semiconductor devices. This has been fueled for instance by the remarkable advances in our ability to fabricate nanostructures such as quantum wells, quantum wires and quantum dots. Despite this contemporary focus on semiconductor "quantum devices," a principal quantum mechanical aspect of the electron - its spin has it accounts for an added quan largely been ignored (except in as much as tum mechanical degeneracy). In recent years, however, a new paradigm of electronics based on the spin degree of freedom of the electron has begun to emerge. This field of semiconductor "spintronics" (spin transport electron ics or spin-based electronics) places electron spin rather than charge at the very center of interest. The underlying basis for this new electronics is the intimate connection between the charge and spin degrees of freedom of the electron via the Pauli principle. A crucial implication of this relationship is that spin effects can often be accessed through the orbital properties of the electron in the solid state. Examples for this are optical measurements of the spin state based on the Faraday effect and spin-dependent transport measure ments such as giant magneto-resistance (GMR). In this manner, information can be encoded in not only the electron's charge but also in its spin state, i. e.
Download or read book Dissertation Abstracts International written by and published by . This book was released on 2008 with total page 994 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Quantum Optical Control of Spins and Excitons in Semiconductor Quantum Dots written by Pochung Chen and published by . This book was released on 2002 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Electron Nuclear Spin Dynamics in Semiconductor Nanostructures written by M. M. Glazov and published by Oxford University Press. This book was released on 2018-09-05 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent years, the physics community has experienced a revival of interest in spin effects in solid state systems. On one hand, the solid state systems, particularly, semiconductors and semiconductor nanosystems, allow us to perform benchtop studies of quantum and relativistic phenomena. On the other hand, this interest is supported by the prospects of realizing spin-based electronics, where the electron or nuclear spins may play a role of quantum or classical information carriers. This book looks in detail at the physics of interacting systems of electron and nuclear spins in semiconductors, with particular emphasis on low-dimensional structures. These two spin systems naturally appear in practically all widespread semiconductor compounds. The hyperfine interaction of the charge carriers and nuclear spins is particularly prominent in nanosystems due to the localization of the charge carriers, and gives rise to spin exchange between these two systems and a whole range of beautiful and complex physics of manybody and nonlinear systems. As a result, understanding of the intertwined spin systems of electrons and nuclei is crucial for in-depth studying and controlling the spin phenomena in semiconductors. The book addresses a number of the most prominent effects taking place in semiconductor nanosystems including hyperfine interaction, nuclear magnetic resonance, dynamical nuclear polarization, spin-Faraday and spin-Kerr effects, processes of electron spin decoherence and relaxation, effects of electron spin precession mode-locking and frequency focussing, as well as fluctuations of electron and nuclear spins.
Download or read book Spin Physics in Semiconductors written by Mikhail I. Dyakonov and published by Springer. This book was released on 2017-10-04 with total page 546 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book offers an extensive introduction to the extremely rich and intriguing field of spin-related phenomena in semiconductors. In this second edition, all chapters have been updated to include the latest experimental and theoretical research. Furthermore, it covers the entire field: bulk semiconductors, two-dimensional semiconductor structures, quantum dots, optical and electric effects, spin-related effects, electron-nuclei spin interactions, Spin Hall effect, spin torques, etc. Thanks to its self-contained style, the book is ideally suited for graduate students and researchers new to the field.
Download or read book Spintronics written by Puja Dey and published by Springer Nature. This book was released on 2021-04-13 with total page 287 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book highlights the overview of Spintronics, including What is Spintronics ?; Why Do We Need Spintronics ?; Comparative merit-demerit of Spintronics and Electronics ; Research Efforts put on Spintronics ; Quantum Mechanics of Spin; Dynamics of magnetic moments : Landau-Lifshitz-Gilbert Equation; Spin-Dependent Band Gap in Ferromagnetic Materials; Functionality of ‘Spin’ in Spintronics; Different Branches of Spintronics etc. Some important notions on basic elements of Spintronics are discussed here, such as – Spin Polarization, Spin Filter Effect, Spin Generation and Injection, Spin Accumulation, Different kinds of Spin Relaxation Phenomena, Spin Valve, Spin Extraction, Spin Hall Effect, Spin Seebeck Effect, Spin Current Measurement Mechanism, Magnetoresistance and its different kinds etc. Concept of Giant Magnetoresistance (GMR), different types of GMR, qualitative and quantitative explanation of GMR employing Resistor Network Theory are presented here. Tunnelling Magnetoresistance (TMR), Magnetic Junctions, Effect of various parameters on TMR, Measurement of spin relaxation length and time in the spacer layer are covered here. This book highlights the concept of Spin Transfer Torque (STT), STT in Ferromagnetic Layer Structures, STT driven Magnetization Dynamics, STT in Magnetic Multilayer Nanopillar etc. This book also sheds light on Magnetic Domain Wall (MDW) Motion, Ratchet Effect in MDW motion, MDW motion velocity measurements, Current-driven MDW motion, etc. The book deals with the emerging field of spintronics, i.e., Opto-spintronics. Special emphasis is given on ultrafast optical controlling of magnetic states of antiferromagnet, Spin-photon interaction, Faraday Effect, Inverse Faraday Effect and outline of different all-optical spintronic switching. One more promising branch i.e., Terahertz Spintronics is also covered. Principle of operation of spintronic terahertz emitter, choice of materials, terahertz writing of an antiferromagnetic magnetic memory device is discussed. Brief introduction of Semiconductor spintronics is presented that includes dilute magnetic semiconductor, feromagnetic semiconductor, spin polarized semiconductor devices, three terminal spintronic devices, Spin transistor, Spin-LED, and Spin-Laser. This book also emphasizes on several modern spintronics devices that includes GMR Read Head of Modern Hard Disk Drive, MRAM, Position Sensor, Biosensor, Magnetic Field sensor, Three Terminal Magnetic Memory Devices, Spin FET, Race Track Memory and Quantum Computing.
Download or read book Semiconductor Quantum Bits written by Fritz Henneberger and published by CRC Press. This book was released on 2016-04-19 with total page 516 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book highlights state-of-the-art qubit implementations in semiconductors and provides an extensive overview of this newly emerging field. Semiconductor nanostructures have huge potential as future quantum information devices as they provide various ways of qubit implementation (electron spin, electronic excitation) as well as a way to transfer
Download or read book Optical Generation and Control of Quantum Coherence in Semiconductor Nanostructures written by Gabriela Slavcheva and published by Springer. This book was released on 2010-06-23 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt: The fundamental concept of quantum coherence plays a central role in quantum physics, cutting across disciplines of quantum optics, atomic and condensed matter physics. Quantum coherence represents a universal property of the quantum s- tems that applies both to light and matter thereby tying together materials and p- nomena. Moreover, the optical coherence can be transferred to the medium through the light-matter interactions. Since the early days of quantum mechanics there has been a desire to control dynamics of quantum systems. The generation and c- trol of quantum coherence in matter by optical means, in particular, represents a viable way to achieve this longstanding goal and semiconductor nanostructures are the most promising candidates for controllable quantum systems. Optical generation and control of coherent light-matter states in semiconductor quantum nanostructures is precisely the scope of the present book. Recently, there has been a great deal of interest in the subject of quantum coh- ence. We are currently witnessing parallel growth of activities in different physical systems that are all built around the central concept of manipulation of quantum coherence. The burgeoning activities in solid-state systems, and semiconductors in particular, have been strongly driven by the unprecedented control of coherence that previously has been demonstrated in quantum optics of atoms and molecules, and is now taking advantage of the remarkable advances in semiconductor fabrication technologies. A recent impetus to exploit the coherent quantum phenomena comes from the emergence of the quantum information paradigm.
Download or read book Quantum Control of Spin Systems in Diamond written by Masashi Hirose (Ph. D.) and published by . This book was released on 2015 with total page 113 pages. Available in PDF, EPUB and Kindle. Book excerpt: The precise control of a system which behaves according to the principles of quantum mechanics is an essential task in order to fully harness the unique properties of quantum mechanics, such as superposition and entanglement, for practical applications. Leveraging the quantum nature of the system would enable, for example, the implementation of quantum computation and quantum metrology. However, any realistic quantum system is inevitably coupled to its environment. The interaction with its surroundings irrevocably destroys the quantum nature of the system: mitigating decoherence is thus one of the central problems in quantum control. In this thesis, we develop novel control methods to protect a qubit from decoherence by two distinct approaches, and demonstrate them experimentally using the nitrogen-vacancy (NV) center in diamond. The first approach rests on an open-loop control scheme and is tailored to improve quantum sensing tasks. We develop a continuous dynamical decoupling (CoDD) method that allows us to tune the degree of protection from a dephasing environment. Exploiting this flexibility, we show that the CoDD can be used to measure magnetic fields with sensitivity comparable to existing methods, while providing superior versatility in practical experimental settings. This protocol can adapt to various sensing conditions that might occur in biological and materials science such as measurement time and sensitive frequency. The second approach exploits a coherent feedback protocol. We take advantage of a long-lived nuclear spin as an ancillary spin to protect the qubit of interest from decoherence. We show that the protocol protects the qubit as long as open-loop dynamical decoupling control schemes and it can be used against more general types of noise than the open-loop protocol. This method thus offers an alternative protocol to protect the qubit from decoherence in quantum computation and quantum metrology.
Download or read book Springer Handbook of Semiconductor Devices written by Massimo Rudan and published by Springer Nature. This book was released on 2022-11-10 with total page 1680 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Springer Handbook comprehensively covers the topic of semiconductor devices, embracing all aspects from theoretical background to fabrication, modeling, and applications. Nearly 100 leading scientists from industry and academia were selected to write the handbook's chapters, which were conceived for professionals and practitioners, material scientists, physicists and electrical engineers working at universities, industrial R&D, and manufacturers. Starting from the description of the relevant technological aspects and fabrication steps, the handbook proceeds with a section fully devoted to the main conventional semiconductor devices like, e.g., bipolar transistors and MOS capacitors and transistors, used in the production of the standard integrated circuits, and the corresponding physical models. In the subsequent chapters, the scaling issues of the semiconductor-device technology are addressed, followed by the description of novel concept-based semiconductor devices. The last section illustrates the numerical simulation methods ranging from the fabrication processes to the device performances. Each chapter is self-contained, and refers to related topics treated in other chapters when necessary, so that the reader interested in a specific subject can easily identify a personal reading path through the vast contents of the handbook.
Download or read book Electron and Nuclear Spin Dynamics in Semiconductor Nanostructures written by M. M. Glazov and published by . This book was released on 2018 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses on the main aspects of electron and nuclear spin dynamics in semiconductor nanostructures. It summarizes main results of theoretical and experimental studies of interactions in spin systems, effects of ultrafast spin manipulation by light, phenomena of spin losses, and the physics of the omnipresent spin noise.
Download or read book Spin and Charge Dynamics in Semiconductor Quantum Dots written by Changxue Deng and published by . This book was released on 2007 with total page 145 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this dissertation, we present detailed studies on the nuclear spin dynamics and relaxation, electron spin decoherence, and non-equilibrium electronic transport in Kondo regime for semiconductor quantum dots. We calculate the coefficients of nuclear spin diffusion with two different methods. It is shown that hyperfine interaction decreases the diffusion coefficients dramatically. We discuss the performance of the coherent spin transfer with the nuclear quantum memory using quantum dot, and calculate the operation fidelity due to nuclear spin dipolar coupling. We also study the possible nuclear spin polarization and relaxation mechanism in a spin-blocked double-dot, and qualitatively explain some of the recent experimental results. We study the electron spin decoherence time (T 2) resulting from hyperfine coupling with the equation-of-motion approach. We show that the transverse electron spin undergoes a complete decay in the long time limit by including higher-order processes. Finally we develop a real-time density matrix method and apply it to study the non-equilibrium electron transport through quantum dots in the context of Kondo effect.
Download or read book Controlling the Dynamics of Classical and Quantum Information in Spin Systems written by Parin B. Dalal and published by . This book was released on 2009 with total page 141 pages. Available in PDF, EPUB and Kindle. Book excerpt: The precise, human control of quantum systems, by its definition, must combine models of the classical and the quantum world into a calculus that supports both. Open, irreversible quantum systems must interact with closed, reversible quantum systems to predict evolutions that are partially open and closed. Inevitably, the problems of quantum measurement, the assumptions of scattering, and the role of spacetime comes under scrutiny. Such considerations have extraordinary practical value: the precise control of a quantum information is the cornerstone of scalable quantum computing. Traditionally, quantum control theory as well as a formalism of redundancy and partial measurements, known as quantum error correction, attempt to remedy systematic quantum-noise and random quantum-noise respectively, but have had mixed success. This dissertation examines how the imprecision of control in quantum and classical spin systems affects the flow of select information to a receiver and how such systems may be optimized against the imprecise scattering of control fields and spins. To this end, this dissertation intertwines the physics of state evolution with the physics of information control in classical and quantum systems. First in classical systems, a method for encoding and decoding classical spin-processing information provides an example of information flow. Then an analytic calculation of a semi-conductor spin channel's information capacity is performed. The results limit the rate of information processing and inform the design of materials for optimal spintronic information-processing in semiconductors. Next, noisy quantum interactions are described, so that the complexities of correcting small, random phase errors using traditional control theory and quantum error correction may be explained. How these noisy processes affect the relevant information flow of a quantum algorithm (derivatives of the Quantum Fourier Transform and Grover Search) is considered, several novel methods of source-coding for these quantum channels are presented and their efficacy calculated. These methods include Unitary-Fault Tolerance, Clifford operations of locally-variant basis, and an entropic controller. Together they show classical systems in the steady state can be used to control scalable, high-precision quantum-computing machines, and ultimately may eliminate all temporal control from quantum operations.
Download or read book Optical Generation and Control of Quantum Coherence in Semiconductor Nanostructures written by Gabriela Slavcheva and published by Springer Science & Business Media. This book was released on 2010-06-01 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt: The fundamental concept of quantum coherence plays a central role in quantum physics, cutting across disciplines of quantum optics, atomic and condensed matter physics. Quantum coherence represents a universal property of the quantum s- tems that applies both to light and matter thereby tying together materials and p- nomena. Moreover, the optical coherence can be transferred to the medium through the light-matter interactions. Since the early days of quantum mechanics there has been a desire to control dynamics of quantum systems. The generation and c- trol of quantum coherence in matter by optical means, in particular, represents a viable way to achieve this longstanding goal and semiconductor nanostructures are the most promising candidates for controllable quantum systems. Optical generation and control of coherent light-matter states in semiconductor quantum nanostructures is precisely the scope of the present book. Recently, there has been a great deal of interest in the subject of quantum coh- ence. We are currently witnessing parallel growth of activities in different physical systems that are all built around the central concept of manipulation of quantum coherence. The burgeoning activities in solid-state systems, and semiconductors in particular, have been strongly driven by the unprecedented control of coherence that previously has been demonstrated in quantum optics of atoms and molecules, and is now taking advantage of the remarkable advances in semiconductor fabrication technologies. A recent impetus to exploit the coherent quantum phenomena comes from the emergence of the quantum information paradigm.
Download or read book Spin Interaction in Semiconductors Mediated by Optical Excitations written by Guillermo Federico Quinteiro Rosen and published by . This book was released on 2006 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt:
