Charge Stripes and Spin Correlations in Copper-oxide Superconductors PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Charge Stripes and Spin Correlations in Copper-oxide Superconductors PDF full book. Access full book title Charge Stripes and Spin Correlations in Copper-oxide Superconductors by . Download full books in PDF and EPUB format.
Author: Publisher: ISBN: Category : Languages : en Pages : 5
Book Description
To obtain superconductivity in a layered copper-oxide compound, it is necessary to introduce charge carriers into the antiferromagnetic CuO2 planes. Recent neutron diffraction studies of the system La{sub 1.6-x}Nd{sub 0.4}Sr(subscript x)CuO4 provide evidence that the dopant-induced holes choose to segregate into periodically-spaced stripes which separate antiferromagnetic domains, in a manner similar to that found in hole-doped La2NiO4. The charge and spin stripe modulations are identified by the appearance of scattering at incommensurate positions. In the Nd-doped system, elastic scattering is observed, corresponding to static stripes. In pure La{sub 2-x}Sr(subscript x)CuO4, the magnetic scattering that is observed is purely inelastic. Where samples with and without Nd, but with the same Sr concentration, have been measured, the incommensurate (IC) splittings of the magnetic signal are found to be essentially identical. It has been proposed that the spin correlations in the two systems are fundamentally the same, thus implying similar charge correlations. The static nature of the stripes in the Nd-doped system is attributed to pinning of the otherwise dynamic correlations by a special distortion of the lattice. That distortion is driven by purely ionic interactions and is stabilized by the smaller ionic radius of the substituted Nd.
Author: Publisher: ISBN: Category : Languages : en Pages : 5
Book Description
To obtain superconductivity in a layered copper-oxide compound, it is necessary to introduce charge carriers into the antiferromagnetic CuO2 planes. Recent neutron diffraction studies of the system La{sub 1.6-x}Nd{sub 0.4}Sr(subscript x)CuO4 provide evidence that the dopant-induced holes choose to segregate into periodically-spaced stripes which separate antiferromagnetic domains, in a manner similar to that found in hole-doped La2NiO4. The charge and spin stripe modulations are identified by the appearance of scattering at incommensurate positions. In the Nd-doped system, elastic scattering is observed, corresponding to static stripes. In pure La{sub 2-x}Sr(subscript x)CuO4, the magnetic scattering that is observed is purely inelastic. Where samples with and without Nd, but with the same Sr concentration, have been measured, the incommensurate (IC) splittings of the magnetic signal are found to be essentially identical. It has been proposed that the spin correlations in the two systems are fundamentally the same, thus implying similar charge correlations. The static nature of the stripes in the Nd-doped system is attributed to pinning of the otherwise dynamic correlations by a special distortion of the lattice. That distortion is driven by purely ionic interactions and is stabilized by the smaller ionic radius of the substituted Nd.
Author: Albert Furrer Publisher: Springer Science & Business Media ISBN: 9780792352266 Category : Science Languages : en Pages : 428
Book Description
The phenomenon of superconductivity - after its discovery in metals such as mercury, lead, zinc, etc. by Kamerlingh-Onnes in 19]] - has attracted many scientists. Superconductivity was described in a very satisfactory manner by the model proposed by Bardeen, Cooper and Schrieffer, and by the extensions proposed by Abrikosov, Gorkov and Eliashberg. Relations were established between superconductivity and the fundamental properties of solids, resulting in a possible upper limit of the critical temperature at about 23 K. The breakthrough that revolutionized the field was made in 1986 by Bednorz and Muller with the discovery of high-temperature superconductivity in layered copper-oxide perovskites. Today the record in transition temperature is 133 K for a Hg based cuprate system. The last decade has not only seen a revolution in the size of the critical temperature, but also in the myriads of research groups that entered the field. In addition, high-temperature superconductivity became a real interdisciplinary topic and brought together physicists, chemists and materials scientists who started to investigate the new compounds with almost all the available experimental techniques and theoretical methods. As a consequence we have witnessed an avalanche of publications which has never occurred in any field of science so far and which makes it difficult for the individual to be thoroughly informed about the relevant results and trends. Neutron scattering has outstanding properties in the elucidation of the basic properties of high-temperature superconductors.
Author: Antonio Bianconi Publisher: Springer Science & Business Media ISBN: 0306471000 Category : Technology & Engineering Languages : en Pages : 557
Book Description
The problem of superconductors has been a central issue in Solid State Physics since 1987. After the discovery of superconductivity (HTSC) in doped perovskites, it was realized that the HTSC appears in an unknown complex electronic phase of c- densed matter. In the early years, all theories of HTSC were focused on the physics of a homogeneous 2D metal with large electron–electron correlations or on a 2D polaron gas. Only after 1990, a novel paradigm started to grow where this 2D metallic phase is described as an inhomogeneous metal. This was the outcome of several experimental evidences of phase separation at low doping. Since 1992, a series of conferences on phase separation were organized to allow scientists to get together to discuss the phase separation and related issues. Following the discovery by the Rome group in 1992 that “the charges move freely mainly in one direction like the water running in the grooves in the corrugated iron foil,” a new scenario to understand superconductivity in the superconductors was open. Because the charges move like rivers, the physics of these materials shifts toward the physics of novel mesoscopic heterostructures and complex electronic solids. Therefore, understanding the striped phases in the perovskites not only provides an opportunity to understand the anomalous metallic state of cuprate superconductors, but also suggests a way to design new materials of technological importance. Indeed, the stripes are becoming a field of general scientific interest.
Author: Albert Furrer Publisher: Springer Science & Business Media ISBN: 9401512841 Category : Science Languages : en Pages : 416
Book Description
The phenomenon of superconductivity - after its discovery in metals such as mercury, lead, zinc, etc. by Kamerlingh-Onnes in 19]] - has attracted many scientists. Superconductivity was described in a very satisfactory manner by the model proposed by Bardeen, Cooper and Schrieffer, and by the extensions proposed by Abrikosov, Gorkov and Eliashberg. Relations were established between superconductivity and the fundamental properties of solids, resulting in a possible upper limit of the critical temperature at about 23 K. The breakthrough that revolutionized the field was made in 1986 by Bednorz and Muller with the discovery of high-temperature superconductivity in layered copper-oxide perovskites. Today the record in transition temperature is 133 K for a Hg based cuprate system. The last decade has not only seen a revolution in the size of the critical temperature, but also in the myriads of research groups that entered the field. In addition, high-temperature superconductivity became a real interdisciplinary topic and brought together physicists, chemists and materials scientists who started to investigate the new compounds with almost all the available experimental techniques and theoretical methods. As a consequence we have witnessed an avalanche of publications which has never occurred in any field of science so far and which makes it difficult for the individual to be thoroughly informed about the relevant results and trends. Neutron scattering has outstanding properties in the elucidation of the basic properties of high-temperature superconductors.
Author: Stephen Edkins Publisher: Springer ISBN: 3319659758 Category : Technology & Engineering Languages : en Pages : 193
Book Description
This thesis reports on the use of scanning tunnelling microscopy to elucidate the atomic-scale electronic structure of a charge density wave, revealing that it has a d-symmetry form factor, hitherto unobserved in nature. It then details the development of an entirely new class of scanned probe: the scanning Josephson tunnelling microscope. This scans the Josephson junction formed between a cuprate superconducting microscope tip and the surface of a cuprate sample, thereby imaging the superfluid density of the sample with nanometer resolution. This novel method is used to establish the existence of a spatially modulated superconducting condensate, something postulated theoretically over half a century ago but never previously observed.
Author: Publisher: ISBN: Category : Languages : en Pages : 5
Book Description
In this study, the concept of intertwined orders has been introduced to describe the cooperative relationship between antiferromagnetic spin correlations and electron (or hole) pair correlations that develop in copper-oxide superconductors. This contrasts with systems in which, for example, charge-density-wave (CDW) order competes for Fermi surface area with superconductivity. La2-xBaxCuO4 with x = 0.125 provides an example in which the ordering of spin stripes coincides with the onset of two-dimensional superconducting correlations. The apparent frustration of the interlayer Josephson coupling has motivated the concept of the pair-density-wave superconductor, a state that theoretical calculations show to be energetically competitive with the uniform d-wave superconductor. Even at x = 0.095, where there is robust superconductivity below 32 K in zero field, the coexistence of strong, low-energy, incommensurate spin excitations implies a spatially modulated and intertwined pair wave function. Recent observations of CDW order in YBa2Cu3O6+x and other cuprate families have raised interesting questions regarding the general role of charge modulations and the relation to superconductivity. While there are differences in the doping dependence of the modulation wave vectors in YBa2Cu3O6+x and La2-xBaxCuO4, the maximum ordering strength is peaked at the hole concentration of 1/8 in both cases. There are also possible connections with the quantum oscillations that have been detected about the same hole concentration but at high magnetic fields. Resolving these relationships remains a research challenge.
Author: Martin Bluschke Publisher: Springer Nature ISBN: 3030479021 Category : Science Languages : en Pages : 170
Book Description
In this thesis chemical and epitaxial degrees of freedom are used to manipulate charge and spin ordering phenomena in two families of transition metal oxides, while taking advantage of state-of-the-art resonant x-ray scattering (RXS) methods to characterize their microscopic origin in a comprehensive manner. First, the relationship of charge density wave order to both magnetism and the "pseudogap" phenomenon is systematically examined as a function of charge-carrier doping and isovalent chemical substitution in single crystals of a copper oxide high-temperature superconductor. Then, in copper oxide thin films, an unusual three-dimensionally long-range-ordered charge density wave state is discovered, which persists to much higher temperatures than charge-ordered states in other high-temperature superconductors. By combining crystallographic and spectroscopic measurements, the origin of this phenomenon is traced to the epitaxial relationship with the underlying substrate. This discovery opens new perspectives for the investigation of charge order and its influence on the electronic properties of the cuprates. In a separate set of RXS experiments on superlattices with alternating nickel and dysprosium oxides, several temperature- and magnetic-field-induced magnetic phase transitions are discovered. These observations are explained in a model based on transfer of magnetic order and magneto-crystalline anisotropy between the Ni and Dy subsystems, thus establishing a novel model system for the interplay between transition-metal and rare-earth magnetism.
Author: Publisher: ISBN: Category : Languages : en Pages : 8
Book Description
Neutron scattering experiments have played a crucial role in characterizing the spin and charge correlations in copper-oxide superconductors. While the data are often interpreted with respect to specific theories of the cuprates, an attempt is made here to distinguish those facts that can be extracted empirically, and the connections that can be made with minimal assumptions.
Author: C Uher Publisher: CRC Press ISBN: 9781566768061 Category : Technology & Engineering Languages : en Pages : 418
Book Description
Proceedings of the joint conferences of the Twenty-Fifth International ThermalConductivity Conference and the Proceedings of the Thirteenth International Thermal Expansion Symposium, on June 13-16, 1999 in Ann Arbor, Michigan USA.
Author: 
Author: 
Author: Albert Furrer
Author: Antonio Bianconi
Author: Albert Furrer
Author: Stephen Edkins
Author: 
Author: 
Author: Martin Bluschke
Author: 
Author: C Uher