Abstract Using a 11.4 GHz, 50-MW, <1 μs, pulsed power source and a TE013-like mode copper cavity, we have been measuring critical magnetic fields of superconductors for accelerator cavity applications. This device can eliminate both thermal and field emission effects due to a short pulse and no electric field at the sample surface. A model of the system is presented in this paper along with a d...

An introduction to and overview of the contents of this Special Issue are given. 32 classes of superconducting materials are discussed, grouped under the three categories ‘‘conventional’’, ‘‘possibly unconventional’’ and ‘‘unconventional’’ according to the mechanism believed to give rise to superconductivity. 2015 Published by Elsevier B.V.

We discuss recent research in the area of critical current densities (JC) in superconductors. This shall cover recent work on newly discovered superconductors, as well as on the magnetic-field dependence of JC .

Inhomogeneity and phase separation in unconventional superconducting materials is a topic of increasing interest, as the competition between phases with different types of ordering is thought to play an important role in the emergence of the high temperature superconducting state. A wide range of experimental techniques are available for investigating the crystallography of these complex materi...

We demonstrate a method of magnetic resonance imaging with single nuclear-spin sensitivity under ambient conditions. Our method employs isolated electronic-spin quantum bits (qubits) as magnetic resonance "reporters" on the surface of high purity diamond. These spin qubits are localized with nanometer-scale uncertainty, and their quantum state is coherently manipulated and measured optically vi...

There are considerable interests in topological superconductivity in condensed matter physics. In this talk, I will present our recent works on topological superconductors and the related phenomena. In particular, I will discuss how topological non-trivial structures in normal states may arise non-trivial quantum phenomena in the superconducting states. As examples, I will discuss odd parity su...

Chemical substitutions at very low level have been proved to be a very effective tool to change important physical parameters in many kinds of materials. These modifications may be the result of, for instance, subtle variations of the position of the Fermi level with respect to the density of states, presence of additional electrons which may change the hole carrier concentration, steric effect...

Single crystals of superconducting BaFe1.8Co0.2As2 were exposed to neutron irradiation in a fission reactor. The defects introduced decrease the superconducting transition temperature (by about 0.3 K) and the upper critical field anisotropy (e.g. from 2.8 to 2.5 at 22 K) and enhance the critical current densities by a factor of up to about 3. These changes are discussed in the context of simila...

The structures, the phase diagrams, and the appearance of a neutron resonance in the superconducting state provide phenomenological evidence which relate the heavy fermion, cuprate and Fe superconductors. Singleand multi-band Hubbard models have been found to describe a number of the observed properties of these materials so that it is reasonable to examine the origin of the pairing interaction...

The discovery of superconducting materials has led to their use in technological marvels such as magnetic-field sensors in MRI machines, powerful research magnets, short transmission cables, and high-speed trains. Despite such applications, the uses of superconductors are not widespread because they function much below room-temperature, hence the costly cooling. Since the discovery of Cu- and F...