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After the discovery of stripelike order in lanthanum-based copper oxide superconductors, charge-ordering instabilities were observed in all cuprate families. However, it has proven difficult to distinguish between unidirectional (stripes) and bidirectional (checkerboard) charge order in yttrium- and bismuth-based materials.We used resonant x-ray scattering to measure the two-dimensional structure factor in the superconductor YBa2Cu3O6+y in reciprocal space. Our data reveal the presence of charge stripe order (i.e., locally unidirectional density waves), which may represent the true microscopic nature of charge modulation in cuprates. At the same time, we find that the well-established competition between charge order and superconductivity is stronger for charge correlations across the stripes than along them, which provides additional evidence for the intrinsic unidirectional nature of the charge order. [ABSTRACT FROM AUTHOR]

Besides superconductivity, copper-oxide high-temperature superconductors are susceptible to other types of ordering. We used scanning tunneling microscopy and resonant elastic x-ray scattering measurements to establish the formation of charge ordering in the high-temperature superconductor Bi2Sr2CaCu2O8+x. Depending on the hole concentration, the charge ordering in this system occurs with the same period as those found in Y-based or La-based cuprates and displays the analogous competition with superconductivity. These results indicate the similarity of charge organization competing with superconductivity across different families of cuprates. We observed this charge ordering to leave a distinct electron-hole asymmetric signature (and a broad resonance centered at +20 milli--electron volts) in spectroscopic measurements, indicating that it is likely related to the organization of holes in a doped Mott insulator. [ABSTRACT FROM AUTHOR]

High-temperature cuprate superconductors display unexpected nanoscale inhomogeneity in essential properties such as pseudogap energy, Fermi surface, and even superconducting critical temperature. Theoretical explanations for this inhomogeneity have ranged from chemical disorder to spontaneous electronic phase separation. We extend the energy range of scanning tunneling spectroscopy on Bi2+ySr2-yCaCu2O8+x, allowing a complete mapping of two types of interstitial oxygen dopants and vacancies at the apical oxygen site. We show that the nanoscale spatial variations in the pseudogap states are correlated with disorder in these dopant concentrations, particularly that of apical oxygen vacancies. [ABSTRACT FROM AUTHOR]

The question of how thin cuprate layers can be while still retaining high-temperature superconductivity (HTS) has been challenging to address, in part because experimental studies require the synthesis of near-perfect ultrathin HTS layers and ways to profile the superconducting properties such as the critical temperature and the superfluid density across interfaces with atomic resolution. We used atomic-layer molecular beam epitaxy to synthesize bilayers of a cuprate metal (La1.65Sr0.45CuO4) and a cuprate insulator (La1.65Sr0.45CuO4) in which each layer is just three unit cells thick. We selectively doped layers with isovalent Zn atoms, which suppress superconductivity and act as markers, to show that this interface HTS occurs within a single CuO2 plane. This approach may also be useful in fabricating HTS devices. [ABSTRACT FROM AUTHOR]

Deals with a study which provided a perspective on the developments of high-temperature copper oxide superconductors. Information on mott insulators, superconductivity and stripes; Characteristics of superconductivity in metals; How conductivity is destroyed.

Presents a study on superconductivity and the c axis spectral weight of high transition temperature (high-Tc) superconductors. Temperature dependence of the c axis spectral weight of high-Tc superconductors as a probe of thermal and quantal fluctuations of the phase of the superconducting order parameter; Behavior of underdoped cuprates as a natural consequence of superconducting pairing without long-ranged phase coherence.

Reports the results of neutron scattering experiments which revealed an interplay between the hole doping, the spin fluctuations, and the superconductivity of the cuprate superconductors. Charge-doping antiferromagnetic insulators as one of the most striking features of the copper oxide superconductors; Phase diagram and structures; The study of spin fluctuations; Conclusions.

Discusses the elastic properties of magnetic flux-line lattices in copper superconductors. Absolute values of the elastic moduli of flux-line arrays; Compressional and smear moduli of the flux-line lattices; Correspondence between the excitations of the flux-line arrays and those of superfluid helium.

Examines the distributions of columnar defects and magnetic flux lines as a function of the defect density in high-transition temperature copper oxide superconductors. Use of an approach that combines chemical etching and magnetic decoration to highlight the distributions simultaneously; Imaging of the distribution of columnar defects by atomic force microscopy.

Discusses the synthesis of a cuprate superconductor containing double mercury layers with a high-pressure, high-temperature technique. Chemical formula of compound with structure similar to that of rock salt; Induction of superconductivity in the system by partial replacement of yttrium with calcium.

The article offers perspective on research reported by Hanaguri et al. elsewhere in the issue on electron-pairing symmetry in superconductors. The research team investigated an alloy of iron, selenium, and tellurium and hypothesized that the pairing mechanism observed may be shared by high-temperature cuprate superconductors. Differences in electron-pairing phenomena between semiconductors and superconductors are discussed. A short history of research on pairing symmetry in iron and cuprate superconductors is presented. A diagram relates spin fluctuations and pairing symmetry.

Discusses a technique for the atomic-scale mixing of mercuric oxide (HgO) and the alkaline earth-copper oxide precursor by means of layer-by-layer pulsed laser deposition (PLD). Problems in the synthesis of high-quality mercury-based cuprate films; Use of a protective cap layer; Annealing in a controlled mercury and oxygen environment; Zero-transition temperature.

Investigates the applicability of superconductors. Implications of the discovery of layered copper oxide for high temperature superconductivity; Role of planar cuprates for high temperature superconductivity; Transformation of insulating compounds into metals.

The article discusses reports within the issue regarding superconductivity research by physicist Da Silva Neto et al. showing the existence of a charge density wave (CDW) in the electron-doped material neodymium-cerium-copper oxide (Nd2-xCexCuO4).

Stabilizing superconductivity at high temperatures and elucidating its mechanism have long been major challenges of materials research in condensed matter physics. Meanwhile, recent progress in nanostructuring offers unprecedented possibilities for designing novel functionalities. Above all, thin films of cuprate and iron-based high-temperature superconductors exhibit remarkably better superconducting characteristics (for example, higher critical temperatures) than in the bulk, but the underlying mechanism is still not understood. Solving microscopic models suitable for cuprates, we demonstrate that, at an interface between a Mott insulator and an overdoped nonsuperconducting metal, the superconducting amplitude is always pinned at the optimum achieved in the bulk, independently of the carrier concentration in the metal. This is in contrast to the dome-like dependence in bulk superconductors but consistent with the astonishing independence of the critical temperature from the carrier density x observed at the interfaces of La2CuO4 and La2-x Sr x CuO4. Furthermore, we identify a self-organization mechanism as responsible for the pinning at the optimum amplitude: An emergent electronic structure induced by interlayer phase separation eludes bulk phase separation and inhomogeneities that would kill superconductivity in the bulk. Thus, interfaces provide an ideal tool to enhance and stabilize superconductivity. This interfacial example opens up further ways of shaping superconductivity by suppressing competing instabilities, with direct perspectives for designing devices.

The article discusses research by Sebastian et al. in the journal "Nature" into the electronic structure of a type of copper oxide in order to understand its superconducting properties.

This section offers news briefs related to science as of January 2014. A complex electronic structure has been found in copper-oxide superconductors. An independent method was developed to forecast ground motion utilizing virtual earthquakes and information obtained from background seismic noise. The genomes of two canine transmissible venereal tumors (CTVTs) and their host dogs were sequenced.