Download or read book Pinning of Magnetic Vortices Subject to Multi well Potential in the Ginzburg Landau Theory of Superconductivity written by Aaron Pakylak and published by . This book was released on 2009 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Pinning of Magnetic Vortices by External Potential microform written by Fridolin S. T. (Fridolin Sze Thou) Ting and published by National Library of Canada = Bibliothèque nationale du Canada. This book was released on 2003 with total page 204 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Vortices in Two Dimensional and Layered Superconducting Model Systems written by Whitney Ryan White and published by . This book was released on 1994 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Pinning with a Variable Magnetic Field of the Two Dimensional Ginzburg Landau Model written by and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Vortex Physics and Flux Pinning written by A. V. Narlikar and published by Nova Publishers. This book was released on 2005 with total page 296 pages. Available in PDF, EPUB and Kindle. Book excerpt: Studies of High Temperature Superconductors, Volume 48 - Vortex Physics & Flux Pinning
Download or read book Theory of Multipole Fluctuation Mediated Superconductivity and Multipole Phase written by Rina Tazai and published by Springer. This book was released on 2021-06-14 with total page 118 pages. Available in PDF, EPUB and Kindle. Book excerpt: A strong spin-orbit interaction and Coulomb repulsion featuring strongly correlated d- and f-electron systems lead to various exotic phase transition including unconventional superconductivity and magnetic multipole order. However, their microscopic origins are long standing problem since they could not be explained based on conventional Migdal-Eliashberg theorem. The book focuses on many-body correlation effects beyond conventional theory for the d- and f-electron systems, and theoretically demonstrates the correlations to play significant roles in “mode-coupling” among multiple quantum fluctuations, which is called U-VC here. The following key findings are described in-depth: (i) spin triplet superconductivity caused by U-VC, (ii) being more important U-VC in f-electron systems due to magnetic multipole degrees of freedom induced by a spin-orbit interaction, and (iii) s-wave superconductivity stabilized cooperatively by antiferromagnetic fluctuations and electron-phonon interaction contrary to conventional understanding. The book provides meaningful step for revealing essential roles of many-body effects behind long standing problems in strongly correlated materials.
Download or read book Suppressible Pinning of Abrikosov Vortices written by Kevin Daniel Smith and published by . This book was released on 2008 with total page 27 pages. Available in PDF, EPUB and Kindle. Book excerpt: A thin superconducting/ferromagnetic heterostructure was constructed for which it was found that the collective pinning of Abrikosov vortices can be induced or prevented depending on the ordering of a ferromagnetic dot array. Arrays in the magnetic vortex state will induce flux pinning if uniformly polarized, but a demagnetized, disordered array will not have collective commensurability with the flux lattice. The system also exhibits field-induced superconductivity as a byproduct of the interaction between magnetic vortex stray fields and penetrating flux quanta.
Download or read book A Numerical Study of Steady state Vortex Configurations and Vortex Pinning in Type II Superconductors written by Sangbum Kim and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In part I, a numerical study of the mixed states in a mesoscopic type-II superconducting cylinder is described. Steady-state configurations and transient behavior ofthe magnetic vortices for various values of the applied magnetic field H are presented. Transitions between different multi-vortex states as H is changed is demonstrated by abrupt changes in vortex configurations and jumps in the B vs H plot. An efficient scheme to determine the equilibrium vortex configuration in a mesoscopic system at any given applied field, not limited to the symmetry of the system, is devised and demonstrated. In part II, a superconducting thin film is subject to a non-uniform magnetic field from a vertical magnetic dipole, consisting of two magnetic monopoles of opposite charges. For a film with constant thickness and with no pins, it has been found that the film carries two pairs of vortex-antivortex in the steady state in the imposed flux range of 2.15
Download or read book Magnetic Force Microscopy Studies of Unconventional Superconductors written by Lan Luan and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Superconductivity is among the most fascinating properties that a material can have. Below the transition temperature $T_c$, electrons condensate into a macroscopic quantum mechanical state and flow without dissipation. The quantum nature of the superconducting state also manifests in its magnetic properties. Superconductors fully expels magnetic field in a weak applied field, referred as Meissner effect. In an intermediate field, superconductors often contain microscopic whirlpools of electrons that carry quantized magnetic flux, called vortices. In this thesis, I present magnetic-force-microscopy (MFM) studies of unconventional superconductors both in the Meissner state and in the mix state. We extend the application of MFM beyond the conventional imaging mode and use it for quantitative analysis. In the mix state, we use MFM manipulating individual vortices with a high level of control and a known force to study the mechanics and dynamics of a single vortex in cuprate superconductors. In the Messiner state, we establish MFM as a novel local technique to measure the magnetic penetration depth $\lambda$ and implement it to study the pairing mechanism of iron-pnictide superconductors. Chapter 1 contains a brief introduction of MFM and its conventional application of imaging. We demonstrate high-spatial resolution images of isolated superconducting vortices. We show that by integrating images of isolated vortices at consecutive heights we are able to reconstruct the force between the MFM tip and vortices. We can also obtain the force by using a tip-vortex model. The two methods agree and both allow us to obtain the force used in vortex manipulation discussed in Chapter 2 and Chapter 3. Chapter 2 discusses the behavior of individual vortices in fully doped YBa$_2$Cu$_3$O$_{7-\delta}$ when subject to a local force. Because the anisotropy of fully doped YBa$_2$Cu$_3$O$_{7-\delta}$ is moderate, the vortex motion can be well described as an elastic string moving through a uniform three dimensional pinning landscape. We find an unexpected and marked enhancement of the response of a vortex to pulling when we wiggle it transversely. In addition, we find enhanced vortex pinning anisotropy that suggests clustering of oxygen vacancies in our sample. We demonstrate manipulation at the nanoscale with a level of control far beyond what has been reported before. We show that a dragged vortex can be used to probe deep into the bulk of the sample and to interact with microscopic structures much smaller than the tip size. Chapter 3 shows the vortex behavior in another limit. In an very underdoped YBa$_2$Cu$_3$O$_{6+x}$ single crystal, a cuprate superconductor with strong anisotropy, a vortex can be regarded as a stack of two-dimensional pancakes with weak interlayer Josephson coupling. We use the MFM tip to split the pancake stacks composing a single vortex and to produce a kinked structure. Our measurements highlight the discrete nature of stacks of pancake vortices in layered superconductors. We also measure the required force in the process, providing the first measurement of the interlayer coupling at the single vortex level. The discovery of iron-pnictide superconductors in 2008 motivates my efforts to locally measure the magnetic penetration depth $\lambda$, one of the two fundamental length scales in superconductors and known to be difficult to measure. Chapter 4 discusses the methodology of measuring $\lambda$ by MFM, which is based on the time-reversed mirror approximation an analytical model of the MFM tip-superconductor interaction in the Meissner state. A calibration run was performed on \YBCO\ single crystals with known $\lambda$. The same time-reversed mirror approximation can be applied to scanning SQUID sysceptometry (SSS) to measure the temperature variation of penetration depth $\Delta\lambda(T)\equiv\lambda(T)-\lambda(0)$. Chapter 5 includes brief introduction of the iron-pnictide superconductors. The multiple conduction bands and the vicinity of the superconducting phase to magnetic phase give additional challenges in $\lambda$ measurements. We demonstrated in this chapter on single crystals of Ba(Fe$_{0.95}$Co$_{0.05}$)$_2$As$_2$ that MFM can measure the absolute value of $\lambda$, as well as obtain its temperature dependence and spatial homogeneity. We observe that $\Delta\lambda(T)$ varies 20 times slower with temperature than previously reported by bulk techniques, and that $\rho_s(T)$ over the full temperature range is well described by a clean two-band fully gapped model, consistent with the proposed $s\pm$ pairing symmetry. Chapter 6 extends the measurements of $\rho_s(T)$ to the family Ba(Fe$_{1-x}$Co$_x$)$_2$As$_2$ with Co doping level $x$ across the superconducting dome. We observe systematic evolution of $\rho_s(T)$ with $x$ that can be summarized as three main trends. First, $\rho_s(0)$ falls more quickly with $T_c$ on the underdoped side of the dome than on the overdoped. Second, the temperature variation of $\rho_s(T)$ at low temperature increases away from optimal doping. Third, $\rho_s(T)$ increases sharply with cooling through the superconducting transition temperature $T_c$ of both optimally doped and underdoped compounds. These observations hint an interplay between magnetism and superconductivity.
Download or read book Superconductivity written by Charles P. Poole and published by Elsevier. This book was released on 2010-07-20 with total page 671 pages. Available in PDF, EPUB and Kindle. Book excerpt: Superconductivity, 2E is an encyclopedic treatment of all aspects of the subject, from classic materials to fullerenes. Emphasis is on balanced coverage, with a comprehensive reference list and significant graphicsfrom all areas of the published literature. Widely used theoretical approaches are explained in detail. Topics of special interest include high temperature superconductors, spectroscopy, critical states, transport properties, and tunneling.This book covers the whole field of superconductivity from both the theoretical and the experimental point of view. Comprehensive coverage of the field of superconductivity Very up-to date on magnetic properties, fluxons, anisotropies, etc. Over 2500 references to the literature Long lists of data on the various types of superconductors
Download or read book Driven Motion of Vortices in Superconductors written by and published by . This book was released on 1995 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: The driven motion of vortices in the solid vortex state is analyzed with the time-dependent Ginzburg-Landau equations. In large-scale numerical simulations, carried out on the IBM Scalable POWERparallel (SP) system at Argonne National Laboratory, many hundreds of vortices are followed as they move under the influence of a Lorentz force induced by a transport current in the presence of a planar defect (similar to a twin boundary in YBa2CU3O-- ). Correlations in the positions and velocities of the vortices in plastic and elastic motion are identified and compared. Two types of plastic motion are observed. Organized plastic motion displaying long-range orientational correlation and shorter-range velocity correlation occurs when the driving forces are small compared to the pinning forces in the twin boundary. Disorganized plastic motion displaying no significant correlation in either the velocities or orientation of the vortex system occurs when the driving and pinning forces axe of the same order.
Download or read book Modern Aspects Of Superconductivity Theory Of Superconductivity Second Edition written by Sergei Kruchinin and published by World Scientific. This book was released on 2021-04-14 with total page 306 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is devoted to superconductivity, which is one of the most interesting problems in physics. In accordance with the outline of the book, it treats the key problems in the field of superconductivity, in particular, it discusses the mechanism(s) of superconductivity. This book is useful for researchers and graduate students in the fields of solid state physics, quantum field theory, and many-body theory.
Download or read book Gravity superconductors Interactions written by Giovanni Modanese and published by Bentham Science Publishers. This book was released on 2012 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Recent developments in gravity-superconductivity interactions have been summarized by several researchers. If gravitation has to be eventually reconciled with quantum mechanics, the macroscopic quantum character of superconductors might actually matter. T"
Download or read book Vortices in Unconventional Superconductors and Superfluids written by Rudolf Huebener and published by Springer Science & Business Media. This book was released on 2002-01-22 with total page 390 pages. Available in PDF, EPUB and Kindle. Book excerpt: Topological defects are generic in continuous media. In the relativistic quantum vacuum they are known as cosmic strings, in superconductors as quantized flux lines, and in superfluids, low-density atomic Bose-Einstein condensates and neutron stars as quantized vortex lines. This collection of articles by leading scientists presents a modern treatment of the physics of vortex matter, mainly applied to unconventional superconductors and superfluids but with extensions to other areas of physics.
Download or read book The Vortex State written by N. Bontemps and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 330 pages. Available in PDF, EPUB and Kindle. Book excerpt: One of the most spectacular consequences of the description of the superfluid condensate in superfluid He or in superconductors as a single macroscopic quantum state is the quantization of circulation, resulting in quantized vortex lines. This book draws no distinction between superfluid He3 and He4 and superconductors. The reader will find the essential introductory chapters and the most recent theoretical and experimental progress in our understanding of the vortex state in both superconductors and superfluids, from lectures given by leading experts in the field, both experimentalists and theoreticians, who gathered in Cargèse for a NATO ASI. The peculiar features related to short coherence lengths, 2D geometry, high temperatures, disorder, and pinning are thoroughly discussed.
Download or read book Theory Of Superconductivity written by J. Robert Schrieffer and published by CRC Press. This book was released on 2018-03-05 with total page 352 pages. Available in PDF, EPUB and Kindle. Book excerpt: Theory of Superconductivity is primarily intended to serve as a background for reading the literature in which detailed applications of the microscopic theory of superconductivity are made to specific problems.
Download or read book Multivalued Fields in Condensed Matter Electromagnetism and Gravitation written by Hagen Kleinert and published by World Scientific. This book was released on 2008 with total page 522 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book lays the foundations of the theory of fluctuating multivalued fields with numerous applications. Most prominent among these are phenomena dominated by the statistical mechanics of line-like objects, such as the phase transitions in superfluids and superconductors as well as the melting process of crystals, and the electromagnetic potential as a multivalued field that can produce a condensate of magnetic monopoles. In addition, multivalued mappings play a crucial role in deriving the physical laws of matter coupled to gauge fields and gravity with torsion from the laws of free matter. Through careful analysis of each of these applications, the book thus provides students and researchers with supplementary reading material for graduate courses on phase transitions, quantum field theory, gravitational physics, and differential geometry.
