Download or read book Proximity Effects in Superconductor Ferromagnet Structures written by and published by . This book was released on 2008 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proximity Effect in Superconductor Ferromagnet Structures written by Fernando Sebastián Bergeret-Sbarbaro and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proximity Effects in Ferromagnet superconductor Structures written by Klaus Halterman and published by . This book was released on 2002 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Inverse Proximity Effect in Superconductor ferromagnet Bilayer Structures written by 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 Proximity Effect in Superconductor ferromagnet Systems written by Jian Zhu and published by . This book was released on 2010 with total page 137 pages. Available in PDF, EPUB and Kindle. Book excerpt: The proximity effect in superconductor (SC) - ferromagnet (FM) system produces many interesting phenomena due to the interplay between two competing orderings, superconductivity and ferromagnetism. This dissertation studies the influence of the orientation of magnetic moments on the superconducting transition temperature (Tc̳) in FM/SC/FM sandwiched structures. The superconducting transition temperature of a FM/SC/FM spin valve depends on the mutual orientation of the magnetic moments of the ferromagnetic layers. This phenomenon, called the spin switch effect, has been previously observed in FM/SC/FM systems as a Tc̳ difference between parallel and antiparallel configurations of the ferromagnetic layers. Both standard (TP̳c̳ TA̳P̳c̳) and inverse (TP̳c̳ TA̳P̳̳c̳) spin switch effects have been reported in different superconducting spin valve systems but the origin of the inverse spin switch effect was not understood. In this dissertation, a discovery of the coexistence of the standard and inverse spin switch effects in Ni1 Fe19 /Nb/Ni1 Fe19 /Ir25 Mn--5 spin valves is described. The measurements reveal that the inverse spin switch effect originates from dissipative flow of vortices induced by stray magnetic field of magnetostatically coupled Neel domain wall pairs in the ferromagnetic layers. This dissertation also studies the Tc̳ of FM/SC/FM sandwiched systems with noncollinear (neither parallel nor antiparallel) orientation of the magnetic moments of the ferromagnetic layers, where the odd triplet superconducting component is predicated to arise. Tc̳ in Cu48 Ni52 /Nb/Cu48 Ni52 trilayers as a function of the angle between the Cu48 Ni52 layer magnetizations is measured. The shape of the observed angular dependence ofTc̳ is in qualitative agreement with SC/FM proximity theories that account for the odd triplet component of the condensate, but large discrepancy in the magnitude is found.
Download or read book Superconductor ferromagnet Nanostructures An Illustration Of The Physics Of Hybrid Nanomaterials written by Oriol T Valls and published by World Scientific. This book was released on 2022-01-14 with total page 279 pages. Available in PDF, EPUB and Kindle. Book excerpt: It used to be difficult to reliably fabricate clean heterostructures using magnetic and superconducting layers. Today this is no longer the case; such reproducible superconductor/ferromagnet heterostructures enable the quantitative study of the rich and varied phenomena associated with ferromagnet/superconductor proximity effects. These structures are eminent, suitable candidates for many switching devices, ranging from non-volatile low power memory elements to quantum computing applications involving Josephson junctions.This book's main purpose is to explain how the equilibrium and transport properties of these heterostructures can be accurately calculated starting from a standard BCS type Hamiltonian. The main techniques, including both analytical and numerical methods, are discussed in detail. Results obtained from these calculations are shown to be in excellent quantitative agreement with experiment.This is a theory book, but the theory is neither abstruse nor esoteric. Knowledge of only introductory graduate physics has been assumed; a solid undergraduate training and a bit of perseverance would also be enough. This book can easily be read and understood by experimentalists, and just about anybody can grasp the basics by referring to the figures and explanations. Quite apart from the manifold applications of superconductor/ferromagnet nanostructures, studying them provides us with considerable insights into fundamental physics and the general study of hybrid nanomaterials.
Download or read book Interplay of Proximity Effects in Superconductor ferromagnet Heterostructures written by Annika Stellhorn and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Superconductivity and Ferromagnetism Interplay in Layered Junctions written by Victor Shelukhin and published by LAP Lambert Academic Publishing. This book was released on 2011-04 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt: The experimental investigations of the direct and the inverse proximity effects in superconductor- ferromagnet (SF) structures are the subjects of this book. The direct proximity effect was investigated by measurements of both critical temperature (Tc) and critical current (Ic) variations. Measurements were focused on -phase shifts observed in the experiments and similarity of the Tc and Ic behavior in our experiments, such as the same periods of oscillations that correspond to equal magnetic lengths in ferromagnetic layers. One of the main findings in my thesis were the observations of the strong oscillations of the critical superconductor current and critical temperature with the period different from previously reported experiments. The inverse proximity effect in SF structures was measured by detecting the induced ferromagnetic order in the superconductor. One of the most important results of these experiments is the experimental observation of the "spin screening effect" which is intimately related to the formation of the triplet component in the superconductor condensate function.
Download or read book Proximity and Flux Pinning Effects in Superconductor ferromagnet Hybrids written by Xavier Palermo and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Superconductor-ferromagnet hybrid systems often bring about new physics and may as well be useful to design new non-volatile, high-density memory devices for superconducting electronics.In this thesis, we study two different types of SF hybrids, each following a possible approach to memory devices, but focusing on fundamental aspects. One is about the proximity effect in oxide heterostructures. In these, triplet correlations appear, that are both superconducting and spin-polarized. These enable using effects from spintronics like GMR, but are also very dependent on interface properties. We investigated these in SFS oxide trilayers by conductance measurements. These showed oscillations which may, in part, be related to these triplet states. We also observed that interface effects affect the electronic properties of the ferromagnet, especially when that layer is thin. Another type of interaction occurs through stray magnetic fields from the domain structures. Recent theoretical proposals suggested that small swirling spin textures called skyrmions could similarly interact with superconductivity through this mechanism. We investigated such coupling in bilayers, in which the superconducting vortex dynamics dominate the transport properties. We found that the presence of skyrmions and domains alike enhances the critical current. It also leads to an unusual Hall effect in the superconducting state. Most of these properties can be explained qualitatively in terms of vortex pinning and guided motion.
Download or read book Proximity Effect in the Superconductor Ferromagnet Nb Fe Layered System written by Thorsten Mühge and published by . This book was released on 1997 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proximity in Hybrid Superconductor Ferromagnetic Structures written by Makram Abd El Qader and published by . This book was released on 2016 with total page 153 pages. Available in PDF, EPUB and Kindle. Book excerpt: The coexistence of superconductivity and ferromagnetic orders has been the subject of study for many years. It well known that these materials possess two competing order parameters; however the two order parameters can coexist under special circumstances inducing interesting physical phenomena. In recent years the demand of ultra-low-power, high density cryogenic memories has brought considerable interest to integrate superconducting and magnetic thin films in one structure to produce novel memory elements. The operation of the device depends on the unusual electronic properties associated with the Superconductor (S) /Ferromagnetic (F) proximity effect. Niobium (Nb) based Josephson junction devices were fabricated with barriers containing two ferromagnetic layers separated by a normal metal space layer. In device operation, electrons in the superconductor are injected into the ferromagnets, causing the superconductor wavefunction to shift its phase and decay in amplitude. Such devices have two different states that depend on the relative magnetization of their ferromagnetic barrier layers, parallel or antiparallel. In these different states, the junctions have different phase shifts and critical currents. Superconducting circuits containing these devices can be designed to operate as memory cells using either one of these outputs. To quantify the shift in phase and amplitude decay of the wavefunction through a common ferromagnet, permalloy, a series of Nb/permalloy/Nb Josephson junctions with varying ferromagnetic layer thicknesses were fabricated. Data have shown that the optimal thickness of a fixed layer composed of permalloy is 2.4 nm, as it shifts the wavefunction phase to Ï0/2, its 0́−pivot point.0́+ If set to precisely this value, the free layer in SFNF'S junctions will switch the junction into either the 0 or Ï0 state depending on its magnetic orientation. To minimize the free-layer switching energy dilute Cu-permalloy alloy [Cu0.7(Ni80Fe20)0.3] with a low magnetic saturation (Ms of ~80 emu/cm3) was used as the free layer. These devices exhibit switching energies at small magnetic fields, demonstrating their potential use for low power non-volatile memory for superconductor circuits. Lastly, to study the proximity effect using other potentially-useful ferromagnetic layers, measurements were performed on Nb/F bilayers and Nb/F/AlOx/Al tunnel junctions with ferromagnets Ni8Fe19, Ni65Fe15Co20, and Pd1-xNix. The dependence of the critical temperature of the bilayers and density of states that propagated through the ferromagnetic layer were studied as a function of thickness. From this study, crucial magnetic and electrical parameters like magnetic coherence lengths (ÎlF), exchange energy (Eex), and the rate of shift in the wavefunction0́9s phase and amplitude as a function of thickness were determined.
Download or read book Superconductors at the Nanoscale written by Roger Wördenweber and published by Walter de Gruyter GmbH & Co KG. This book was released on 2017-09-11 with total page 590 pages. Available in PDF, EPUB and Kindle. Book excerpt: By covering theory, design, and fabrication of nanostructured superconducting materials, this monograph is an invaluable resource for research and development. Examples are energy saving solutions, healthcare, and communication technologies. Key ingredients are nanopatterned materials which help to improve the superconducting critical parameters and performance of superconducting devices, and lead to novel functionalities. Contents Tutorial on nanostructured superconductors Imaging vortices in superconductors: from the atomic scale to macroscopic distances Probing vortex dynamics on a single vortex level by scanning ac-susceptibility microscopy STM studies of vortex cores in strongly confined nanoscale superconductors Type-1.5 superconductivity Direct visualization of vortex patterns in superconductors with competing vortex-vortex interactions Vortex dynamics in nanofabricated chemical solution deposition high-temperature superconducting films Artificial pinning sites and their applications Vortices at microwave frequencies Physics and operation of superconducting single-photon devices Josephson and charging effect in mesoscopic superconducting devices NanoSQUIDs: Basics & recent advances Bi2Sr2CaCu2O8 intrinsic Josephson junction stacks as emitters of terahertz radiation| Interference phenomena in superconductor-ferromagnet hybrids Spin-orbit interactions, spin currents, and magnetization dynamics in superconductor/ferromagnet hybrids Superconductor/ferromagnet hybrids
Download or read book The Superconductor ferromagnet Proximity Effect Studied by Scanning Tunneling Microscopy written by Yoav Kalcheim and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Proximity Effect in High Tc Superconductor ferromagnet Bilayers Studied by Scanning Tunneling Spectroscopy written by Itay Asulin and published by . This book was released on 2009 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Superconducting Proximity Effect in Mesoscopic Nanostructures written by Mohammad Ali Maleki and published by LAP Lambert Academic Publishing. This book was released on 2011-02 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book consists of two parts. In the first part, we investigate the superconducting proximity effect in a clean magnetic structure consisting of two ferromagnetic layered domains with antiparallel magnetizations in contact with a superconductor. Within the quasiclassical Green's function approach we find that the penetration of the superconducting correlations into the magnetic domains can be enhanced as compared to the corresponding single domain structure. This enhancement depends on an effective exchange field which is determined by the thicknesses and exchange fields of the two domains. In the second part, we study the superconducting proximity effect in a clean nonmagnetic metal in contact with a ferromagnetic superconductor which has a nonunitary f-wave triplet order parameter. Using the quasiclassical Green's function approach, we solve the Eilenberger equation analytically in a non-self-consistent form. The density of states is obtained in the bulk of the ferromagnetic superconductor and it is plotted versus the energy. We have compared energy-dependence of density of states with the corresponding dependences for s-wave and d-wave superconductors.
Download or read book Handbook of Superconductivity written by David A. Cardwell and published by CRC Press. This book was released on 2022-07-05 with total page 1088 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the first of three volumes of the extensively revised and updated second edition of the Handbook of Superconductivity. The past twenty years have seen rapid progress in superconducting materials, which exhibit one of the most remarkable physical states of matter ever to be discovered. Superconductivity brings quantum mechanics to the scale of the everyday world where a single, coherent quantum state may extend over a distance of metres, or even kilometres, depending on the size of a coil or length of superconducting wire. Viable applications of superconductors rely fundamentally on an understanding of this intriguing phenomena and the availability of a range of materials with bespoke properties to meet practical needs. This first volume covers the fundamentals of superconductivity and the various classes of superconducting materials, which sets the context and background for Volumes 2 and 3. Key Features: Covers the depth and breadth of the field Includes contributions from leading academics and industry professionals across the world Provides hands-on guidance to the manufacturing and processing technologies A comprehensive reference, this handbook is suitable for both graduate students and practitioners in experimental physics, materials science and multiple engineering disciplines, including electronic and electrical, chemical, mechanical, metallurgy and others.
Download or read book Study of the Influence of Domain Walls in the Superconductor Ferromagnet Proximity Effect written by Edgar Javier Patiño and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
