Electron Spin Resonance (ESR) Based Quantum Computing - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Electron Spin Resonance (ESR) Based Quantum Computing write by Takeji Takui. This book was released on 2016-10-12. Electron Spin Resonance (ESR) Based Quantum Computing available in PDF, EPUB and Kindle. This book addresses electron spin-qubit based quantum computing and quantum information processing with a strong focus on the background and applications to EPR/ESR technique and spectroscopy. It explores a broad spectrum of topics including quantum computing, information processing, quantum effects in electron-nuclear coupled molecular spin systems, adiabatic quantum computing, heat bath algorithmic cooling with spins, and gateway schemes of quantum control for spin networks to NMR quantum information. The organization of the book places emphasis on relevant molecular qubit spectroscopy. These revolutionary concepts have never before been included in a comprehensive volume that covers theory, physical basis, technological basis, applications, and new advances in this emerging field. Electron Spin Resonance (ESR) Based Quantum Computing, co-edited by leading and renowned researchers Takeji Takui, Graeme Hanson and Lawrence J Berliner, is an ideal resource for students and researchers in the fields of EPR/ESR, NMR and quantum computing. This book also • Explores methods of harnessing quantum effects in electron-nuclear coupled molecular spin systems • Expertly discusses applications of optimal control theory in quantum computing • Broadens the readers’ understanding of NMR quantum information processing
Magnetic Resonance Studies of Issues Critical to Solid State Quantum Computer
Magnetic Resonance Studies of Issues Critical to Solid State Quantum Computer - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Magnetic Resonance Studies of Issues Critical to Solid State Quantum Computer write by Nakorn Suwuntanasarn. This book was released on 2008. Magnetic Resonance Studies of Issues Critical to Solid State Quantum Computer available in PDF, EPUB and Kindle. The spins of phosphorus doped in silicon are potential candidates for a quantum computing device, with models based on the use of nuclear and/or electron spins suggested. For a quantum computing device, several essential criteria must be demonstrated before any physical implementation, and these include qubit control gates, long decoherence time and scalability. Scalability and compatibility with existing fabrication technologies are strong points in favour of a silicon based system. For spin based schemes, silicon has the potential to provide a host with zero nuclear spin (isotopically purifed 28Si) and also the phosphorus donor provides both nuclear and electron half integer spins (ideal case). In this work, a magnetic resonance method (electron spin resonance) was utilised to investigate these critical issues (controllable quantum gates and decoherence time) for the electron spins of phosphorus donors in silicon. Electron spin resonance (ESR) studies of an ensemble of phosphorus electron spins in silicon were conducted via both continuous wave and pulsed methods. For pulsed ESR operations, two low temperature (4 K and millikelvin) X-band pulsed ESR systems were built. They were designed especially to suit Si:P decoherence time measurements. The design, modelling, construction and evaluation of the probe heads are described. With the aid of computer simulations, the performance of the probe heads was optimised and a rectangular loop gap resonator was found to be the most suitable for wafer type samples. The resonant frequency, quality factor, and coupling coeffcient were calculated via simulation and are in reasonable agreement with experimental results. This demonstrates the effectiveness of such simulations as a tool for optimising the probe head performance. A millikelvin pulsed ESR system was set up through the combination of a dilution refrigerator, superconducting magnet and the in-house construction of a pulsed ESR spectrometer. This novel system allows pulsed ESR experiments on an ensemble system to be realised down to the millikelvin temperature range, hence providing conditions considered most favourable for quantum computing studies. The use of light in combination with the pulsed ESR systems was also explored in an endeavour to overcome the problem of very long spin-lattice relaxation time, T1, allowing the decoherence time to be measured more effciently. With these novel low temperature pulsed ESR units, two-pulse electron spin echo experiments were conducted on phosphorus donors in silicon (both natural silicon (natSi) and 28Si) with the phosphorus concentration in the range of 1015- 1016 P/cm3 and to lower temperatures than previously investigated. Decoherence times measured for both natSi:P and 28Si:P (with similar donor concentrations) were longer than previously reported. Discussions on several effective ways to obtain even longer Si:P decoherence times including variations to sample configurations and experimental conditions are presented. In addition to the pulsed ESR studies, the Si:P controllable quantum gate functions, A gate and J gate, were examined by the continuous wave technique via Stark shift and exchange interaction experiments respectively. Stark shift experiments on bulk samples were carried out to investigate possible manipulation of the spins by the applied electric field. Continuous wave ESR was also used to examine low energy ion implanted Si:P devices, both by single (P+) and dimer (P+2 ) implanted donors. The outcomes from these studies provide materials information useful in formulating a strategy toward the Si:P device fabrication via the top down approach.
Designing a Quantum Computer Based on Pulsed Electron Spin Resonance
Designing a Quantum Computer Based on Pulsed Electron Spin Resonance - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Designing a Quantum Computer Based on Pulsed Electron Spin Resonance write by Gavin W. Morley. This book was released on 2005. Designing a Quantum Computer Based on Pulsed Electron Spin Resonance available in PDF, EPUB and Kindle.
Control Techniques in Spin Based Quantum Computation
Control Techniques in Spin Based Quantum Computation - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Control Techniques in Spin Based Quantum Computation write by Hemant Katiyar. This book was released on 2019. Control Techniques in Spin Based Quantum Computation available in PDF, EPUB and Kindle. Working on quantum systems entail different interests, for example, working on fundamental understanding of quantum systems also lay foundation for better quantum computation techniques. A test for whether a system is behaving quantum mechanically or classically is devised by Leggett and Garg in form of inequalities, called Leggett-Garg Inequalities (LGI). Such Inequalities are violated by a system whose evolution is governed by quantum mechanics. A precise experiment to violate LGIs require a guarantee that the measurement does not affect the system or its future dynamics. These Inequalities were proposed for dichotomic systems,systems which can have two outcomes. Here we present an LG experiment on a three-level quantum system, which theoretically have larger quantum upper bound than that of a two-level quantum system. This larger violation also provides a bigger buffer to taking in account of the various experimental imperfections. Performing a quantum computing task requires precise level of control to initialize, perform and measure the quantum system. With increasing size of the quantum processor the challenge is to maintain optimal control. Nuclear Magnetic Resonance (NMR) has always been a very faithful test-bed for quantum processing ideas. In NMR, we perform Radio Frequency (RF) pulses to control and steer the system to the desired state. Most used method to derive the exact frequency and amplitude of these pulses for a given task is based on gradient. Although systematic, one have to simulate these pulses on a classical computer first, which makes the task very inefficient. We report a a way of performing optimization with a hybrid quantum-classical scheme. This scheme helps us perform classically harder computational tasks on the quantum processor. We optimize pulses which drive our system from 7-coherence state to 12-coherence state on a 12-qubit NMR processor. Electron Spin Resonance (ESR) employs the same techniques as of NMR but having advantage in larger polarization compared to later. Although this does not imply better control, cause the frequency at which pulses are required to control an ESR system fall into microwave region. Microwave frequency are harder to control electronically, thus making it harder for performing ESR quantum computing. The hybrid scheme used in NMR experiment relies on some ideal pulses which are needed to be optimized classically. We alleviate this requirement by using finite difference method of calculating gradient. We compare these methods with the earlier methods to show the superiority of such a scheme. State-to-state transfer pulses are sufficient for most of the quantum computing task, but, an universal quantum information implementation requires state independent pulses. The techniques used in optimizing state-to-state pulses can be modified to optimize for a state independent pulse. We show that this methods scale polynomially with the number of qubits and is general in terms of its implementation. We further reduce the resource requirement by using a NMR related implementation.
Electron Paramagnetic Resonance
Electron Paramagnetic Resonance - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Electron Paramagnetic Resonance write by Victor Chechik. This book was released on 2016-11-30. Electron Paramagnetic Resonance available in PDF, EPUB and Kindle. The topics covered in this volume describe contrasting types of Electron Paramagnetic Resonance (EPR) application, including inorganic paramagnetic systems, spin-labeling in highly dynamic systems such as RNAs and IDPs and applications of nitroxides in host:guest chemistry. EPR applications remain very significant in modern science and this volume compiles critical coverage of developments in the recent literature by a hand-picked group of researchers at the cutting-edge of the field. Providing a snap shot of the area, this book is a useful addition to any library supporting this research.
