Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

Phd by thesis

Giant and isotropic magnetoresistance as huge as −53% was observed in magnetic manganese oxide La0.72Ca0.25MnOz films with an intrinsic antiferromagnetic spin structure. We ascribe this magnetoresistance to spin‐dependent electron scattering due to spin canting of the manganese oxide.

31p-S-4 Giant Magnetoresistance in Magnetic Manganese Oxide with Intrinsic Antiferromagnetic Spin Structure

Since the first days of high-Tc superconductivity, the materials science and the physics of grain boundaries in superconducting compounds have developed into fascinating fields of research. Unique electronic properties, different from those of the grain boundaries in conventional metallic superconductors, have made grain boundaries formed by high-Tc cuprates important tools for basic science. They are moreover a key issue for electronic and large-scale applications of high-Tc superconductivity. The aim of this review is to give a summary of this broad and dynamic field. Starting with an introduction to grain boundaries and a discussion of the techniques established to prepare them individually and in a well-defined manner, the authors present their structure and transport properties. These provide the basis for a survey of the theoretical models developed to describe grain-boundary behavior. Following these discussions, the enormous impact of grain boundaries on fundamental studies is reviewed, as well as high-power and electronic device applications.

/pdf/grain-boundaries-in-high-t-c-superconductors-2widq11ljn.pdf

Grain boundaries in high- T c superconductors

The high-temperature copper oxide superconductors are of fundamental and enduring interest. They not only manifest superconducting transition temperatures inconceivable 15 years ago, but also exhibit many other properties apparently incompatible with conventional metal physics. The materials expand our notions of what is possible, and compel us to develop new experimental techniques and theoretical concepts. This article provides a perspective on recent developments and their implications for our understanding of interacting electrons in metals.

https://science.sciencemag.org/content/sci/288/5465/468.full.pdf

Advances in the physics of high-temperature superconductivity

Interest in superconducting microresonators has grown dramatically over the past decade. Resonator performance has improved substantially through the use of improved geometries and materials as well as a better understanding of the underlying physics. These advances have led to the adoption of superconducting microresonators in a large number of low-temperature experiments and applications. This review outlines these developments, with particular attention given to the use of superconducting microresonators as detectors.

Superconducting Microresonators: Physics and Applications

We have observed the quantization of magnetic flux in a high-Tc yttrium-based ceramic superconductor1 and obtain a value for the flux quantum in this material. The value of the flux quantum, h/2e where h is Planck's constant and e is the electron charge, implies that the charge carriers of superconductivity are electron pairs.

Flux quantization in a high- T c superconductor

Planar superconducting resonators are now being increasingly used at mK temperatures in a number of novel applications. We have experimentally investigated three types of niobium resonators including a lumped-element design fabricated on sapphire and ${\text{SiO}}_{2}/\text{Si}$ substrates. They all exhibit a nonmonotonic temperature dependence of their center frequency which could be accurately described by resonant absorption by two-level fluctuators (TLF). By analyzing the temperature dependence we extracted information about the distribution of TLF. Our results are consistent with there being a spread of TLF at the interface between superconductor and substrate.

Properties of superconducting planar resonators at millikelvin temperatures

We describe measurements on microwave coplanar resonators designed for quantum bit experiments. Resonators have been patterned onto sapphire and silicon substrates, and quality factors in excess of a million have been observed. The resonant frequency shows a high sensitivity to magnetic field applied perpendicular to the plane of the film, with a quadratic dependence for the fundamental, second, and third harmonics. Frequency shift of hundreds of linewidths can be obtained with no change in the quality factor.

Magnetic field tuning of coplanar waveguide resonators

The recent discovery1 of ceramic superconductors with high transition temperatures opens the way for the development of superconducting devices operating at liquid-nitrogen temperature (77 K). Of particular interest is the possibility of constructing a radio-frequency superconducting quantum interference device (r.f. SQUID), for use as an extremely sensitive magnetometer2. The operation of the r.f. SQUID is also of interest as a means of investigating superconductivity in the new ceramic materials. Here we report the construction of an r.f. SQUID based on the multi-phase high-temperature superconducting ceramic Y1.2Ba0.8CuO4 (ref. 1). We have used this as a magnetometer operating at 4.2 K and have observed unusual SQUID behaviour which may be due to the presence of many weakly coupled superconducting paths within the material1,3. We have also observed SQUID behaviour at temperatures as high as 45 K.

Radio-frequency SQUID operation using a ceramic high-temperature superconductor

We propose a scheme for circuit quantum electrodynamics with a superconducting flux?qubit coupled to a high-Q coplanar resonator. Assuming realistic circuit parameters, we predict that it is possible to reach the strong coupling regime. Routes to metrological applications, such as single-photon generation and quantum non-demolition measurements, are discussed.

https://iopscience.iop.org/article/10.1088/0953-2048/20/8/016/pdf

C. M. Muirhead

Papers

Flux quantization in a high- T c superconductor

Properties of superconducting planar resonators at millikelvin temperatures

Magnetic field tuning of coplanar waveguide resonators

Radio-frequency SQUID operation using a ceramic high-temperature superconductor

Circuit QED with a flux qubit strongly coupled to a coplanar transmission line resonator