London theory was developed by Fritz London in 1935 to describe the Meissner effect. This theory leads to the introduction of the penetration depth to describe the extent of magnetic field penetration, λ into type I superconductors. The penetration depth is also important in type II superconductors and describes the extent of flux penetration near vortices as well as at surfaces. Prior to his s...

In this paper, we review the low energy electronic structure of the kinetic energy driven d-wave cuprate superconductors. We give a general description of the chargespin separation fermion-spin theory, where the constrained electron is decoupled as the gauge invariant dressed holon and spin. In particular, we show that under the decoupling scheme, the charge-spin separation fermion-spin represe...

By taking account of the complex relaxation times for sand d-wave order parameters in the time-dependent Ginzburg– Landau equations, our results indicate that the imaginary parts of the relaxation times can change the sign of the Hall angle for mixed sand d-wave superconductors. The effect of the concentration of the nonmagnetic impurities on the Hall angle is investigated, and it is found that...

The superconducting state is formed by the condensation of a large number of Cooper pairs. The normal state electronic properties can give significant influence on the superconducting state. For usual type-II superconductors, the vortices are cylinder like with a round cross-section. For many two dimensional superconductors, such as Cuprates, albeit the in-plane anisotropy, the vortices general...

The Nb-based superconductor-insulator-superconductor (SIS) tunnel junctions have been broadly used in many applications. The critical current density ( ), one of the most important parameters of SIS tunnel junction, is usually controlled by the oxygen exposure ( 2) of the Al oxidation process. R. E. Miller et al. demonstrated the relation between and oxygen exposure using the SNEP process. Howe...

Magnetic measurements on a high-T, superconductor YBa2Cu30q are reported. Diamagnetism sets in, at low fields, below a temperature T=90 K. At low T the field-cooled magnetization becomes positive again. We show that the low-T phase is still superconducting and the apparent reentry behavior is due to strong paramagnetic contributions. Glassy features appear below a temperature whose field depend...

We study the Josephson effect between two noncentrosymmetric superconductors (NCSs) with opposite polarization vectors of Rashba spin–orbit coupling (RSOC). We find a 0–π transition driven by the triplet–singlet ratio of NCSs. Different from conventional 0–π transitions, the Andreev bound states change their energy range instead of phase shift in the 0–π transition found here. This novel proper...

The superconducting transition temperature (Tc) of tetragonal Fe1+δSe was enhanced from 8.5 K to 44 K by chemical structure modification. While insertion of large alkaline cations like K or solvated lithium and iron cations in the interlayer space, the [Fe2Se2] interlayer separation increases significantly from 5.5 Å in native Fe1+δSe to >7 Å in KxFe1-ySe and to >9 Å in Li1-xFex(OH)Fe1-ySe, we ...

The 1111-type iron-based superconductor LnFeAsO(1-x)Fx (Ln stands for lanthanide) is the first material with a Tc above 50 K, other than cuprate superconductors. Electron doping into LaFeAsO by H, rather than F, revealed a double-dome-shaped Tc-x diagram, with a first dome (SC1, 0.05<x<0.20) and a second dome (SC2, 0.2<x<0.5). Here, we report the Tc for the whole hydrogen-doping range in LaFeAs...