Download or read book Effect of Spin Fluctuations on the Ultrasonic Attenuation in Itinerant Electron Systems with Helical Spin Structures written by Kenji Makoshi and published by . This book was released on 1978 with total page 27 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Journal of the Physical Society of Japan written by and published by . This book was released on 1979 with total page 1018 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Journal of the Acoustical Society of America written by and published by . This book was released on 1977 with total page 1334 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Japanese Journal of Applied Physics written by and published by . This book was released on 1980 with total page 1940 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Spin Fluctuations in Itinerant Electron Magnetism written by Toru Moriya and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 253 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ferromagnetism of metallic systems, especially those including transition metals, has been a controversial subject of modern science for a long time. This controversy sterns from the apparent dual character of the d-electrons responsible for magnetism in transition metals, i.e., they are itinerant elec trons described by band theory in their ground state, while at finite tem peratures they show various properties that have long been attributed to a system consisting of local magnetic moments. The most familiar example of these properties is the Curie-Weiss law of magnetic susceptibility obeyed by almost all ferromagnets above their Curie temperatures. At first the problem seemed to be centered around whether the d-elec trons themselves are localized or itinerant. This question was settled in the 1950s and early 1960s by various experimental investigations, in particular by observations of d-electron Fermi surfaces in ferromagnetic transition metals. These observations are generally consistent with the results of band calculations. Theoretical investigations since then have concentrated on explaining this dual character of d-electron systems, taking account of the effects of electron-electron correlations in the itinerant electron model. The problem in physical terms is to study the spin density fluctuati·ons, which are ne glected in the mean-field or one-electron theory, and their influence on the physical properties.
Download or read book Metals Abstracts written by and published by . This book was released on 1981 with total page 1278 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Physics Briefs written by and published by . This book was released on 1993 with total page 1180 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Metals Abstracts Index written by and published by . This book was released on 1981 with total page 706 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effect of Spin Fluctuations on Itinerant Electron Antiferromagnetism written by Hideo Hasegawa and published by . This book was released on 1974 with total page 47 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Alloys Index written by and published by . This book was released on 1981 with total page 792 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Spin Fluctuation Theory of Itinerant electron Systems written by Hideo Hasegawa and published by . This book was released on 1981 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Spin orbit Coupling Effects in Two Dimensional Electron and Hole Systems written by Roland Winkler and published by Springer. This book was released on 2014-03-12 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first part provides a general introduction to the electronic structure of quasi-two-dimensional systems with a particular focus on group-theoretical methods. The main part of the monograph is devoted to spin-orbit coupling phenomena at zero and nonzero magnetic fields. Throughout the book, the main focus is on a thorough discussion of the physical ideas and a detailed interpretation of the results. Accurate numerical calculations are complemented by simple and transparent analytical models that capture the important physics.
Download or read book Relativistic Electronic Transport Theory written by Stephan Lowitzer and published by . This book was released on 2010 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Spintronics is an emerging technology that exploits the intrinsic spin of the electron and its associated magnetic moment in addition to its fundamental electronic charge. The central issue of this multidisciplinary field is the manipulation of the spin degree of freedom in solid-state systems. Discoveries in recent years have inspired a new route in spintronic research which needs no ferromagnetic components. The research field "spintronic without magnetism" is based on the possibility to manipulate electric currents via spin-orbit coupling only. The spin Hall effect (SHE) is one of the most promising effects for the generation of spin polarized currents which is even present in non-magnetic materials. The SHE appears when an electric current flows through a medium with spin-orbit coupling present, leading to a spin-current perpendicular to the charge current. In this work the SHE as well as the anomalous Hall effect (AHE) are investigated on a first principles level using the spin-polarized fully relativistic Korringa-Kohn-Rostoker Green's function method (SPR-KKR-GF) in conjunction with the linear response Kubo-Streda formalism. Intrinsic as well as extrinsic contributions to the SHE/AHE are treated on equal footing. This opened up for the first time the possibility to reliably decompose the SHE/AHE into skew and side-jump scattering as well as intrinsic contributions in a quantitative manner.
Download or read book Suppression of Collective Fluctuations and Generation of Entanglement in a Spin Ensemble written by Yu Luo and published by . This book was released on 2017-01-26 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation, "Suppression of Collective Fluctuations and Generation of Entanglement in a Spin Ensemble" by Yu, Luo, 罗郁, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: Spin degrees of freedom have been extensively explored in the context of quantum information processing. Many proposals of quantum computation architectures use spins as carriers of quantum of information. A central problem is to efficiently generate quantum entanglement between spin qubits which proves to be a crucial resource for quantum information tasks. On the other hand, uncontrollable spin degrees of freedom in the environment of spin qubits are the major causes of errors at low temperature, for example, the lattice nuclear spins hyperfine coupled to single electron spin qubit localized in semiconductor nano-structures. An outstanding problem for scalable quantum computation is to suppress the collective fluctuations from such spin baths so that the coherence time of the spin qubit can be improved. With these two motivations, the problems of suppressing collective spin fluctuations and generating entanglement in various spin ensembles are addressed in this thesis. In the first half of the thesis, two approaches are introduced for suppressing the collective fluctuations in the nuclear spin bath so that the quantum coherence time of electron spin qubit in semiconductor quantum dots can be improved. The first approach works for a coupled double dot system. A theory for the interaction with the nuclear spins is developed when the two-electron singlet state is in resonance with one of the triplet state in moderate external magnetic field. At this resonance condition, the nuclear-electron flip-flop process caused by the hyperfine interaction can lead to a feedback mechanism, which can be used to suppress the nuclear hyperfine field. The second approach works for a single dot system. It is shown that strong pumping of the nuclear spins in dynamic nuclear polarization processes can saturate the nuclear spin bath towards the collective "dark states." In such dark states, the transverse nuclear field fluctuation can be substantially suppressed compared to the value at thermal equilibrium. Two physical schemes are proposed to realize the nuclear dark states for suppression of the nuclear field fluctuations. In the second half of the thesis, schemes are presented for generating large scale quantum entanglement in two types of spin qubit systems. For atomic spin qubits in optical lattices, schemes are proposed on how to prepare pure spin coherent state (SCS) with low collective spin by incoherent pumping with collective spin raising and lowering operations. Such SCS realize networks of mutually entangled spins which can be idea resources for the quantum telecloning algorithm. For donor nuclear spin qubits in silicon architecture, proposals are shown on how to deterministic prepare Dicke states which constitute an important class of multipartite entangled states. Our scheme is capable of preparing both symmetric and asymmetric Dicke states which form a complete basis set of the spin Hilbert space. The required controls are in situ to the prototype Kane's quantum computer. The preparation is robust because each desired Dicke state is the steady state under designed pumping process. The schemes presented here also make possible the construction of decoherence free subspaces where quantum information is protected from collective noises. DOI: 10.5353/th_b4832979 Subjects: Quantum theory - Data processing
Download or read book Coexistance of Spin and Charge Density Fluctuations in Strongly Correlated Systems written by Fuxiang Han and published by . This book was released on 1993 with total page 286 pages. Available in PDF, EPUB and Kindle. Book excerpt: Spin and charge density fluctuations are important excitations in the strongly correlated systems, especially in the recently discovered high temperature superconductors. Several different theories on high temperature superconductors have been proposed based on spin fluctuations. However, experiments have also shown the existence of strong charge fluctuations. It is, therefore, desirable to investigate the physical consequences of the coexistence of strong spin and charge density fluctuations. As a first step toward a full understanding of both spin and charge excitations, a self-consistent theory is established. In this self-consistent theory, there are three important quantities, the spin susceptibility, the charge susceptibility, and the phonon Green's function. These three quantities are coupled together by the electron-phonon and phonon-spin fluctuation interactions. The phonon-spin fluctuation interaction is derived by making use of the spin-orbital coupling. For a strongly correlated system, the spin and charge density excitations have to be considered self-consistently. They are intimately related. The effects of antiparamagnons on phonons are also investigated. Antiparamagnons can have dramatic effects on phononic properties. It is found that new modes are formed in the presence of antiferromagnetic spin fluctuations. The de Haas-van Alphen effect in marginal and nearly antiferromagnetic Fermi liquids is studied. It is found that the de Haas-van Alphen frequency is unaffected by the anomalous response functions of the marginal and nearly antiferromagnetic Fermi liquids due to the absence of real parts of self-energies on the imaginary frequency axis.
Download or read book Critical Fluctuations in a Spin Glass written by Gary F. Hawkins and published by . This book was released on 1978 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Current Programs written by and published by . This book was released on 1976 with total page 526 pages. Available in PDF, EPUB and Kindle. Book excerpt:
