The phenomenon of superconductivity was first observed in 1912 in the laboratory of Heike Kamerlingh Onnes, at the University of Leiden (Holland). At low temperatures certain materials (about 800 superconducting compounds have been recently tabulated by Poole and Farch, 2000) suddenly lose their resistance to the flow of electricity on cooling. The phenomenon remained a laboratory curiosity unt...

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 .

Superconductivity and magnetism are typically antithetical forms of order. After all, in conventional superconductors, magnetic impurities are destructive to superconductivity as they break Cooper pairs [1]. But the discovery in 1979 of so-called heavy fermion superconductivity, found near an antiferromagnetic phase, led to a shift in thinking on this subject [2]. Since then, some of the most i...

A generalized form of Ginzburg–Landau theory is proposed which explains the non-hexagonal flux-line lattice found both in metallic and magnetic superconductors without invoking any anisotropic material-dependent properties. The Gibbs energy density postulated for magnetic superconductors (g) is of the form g(B, T ) = α|ψ |2 + 1 2β|ψ |4 + [1/(2m)]|(−ih̄∇−2eA)ψ |2 + ∫ (B/μ0 − Mions) · dB − (B/μ0 −...

Linear defects are generic in continuous media. In quantum systems they appear as topological line defects which are associated with a circulating persistent current. In relativistic quantum vacuum they are known as cosmic strings, in superconductors as quantized flux lines, and in superfluids and low-density atomic Bose-Einstein condensates as quantized vortex lines. We discuss unconventional ...

Unconventional superconductors are characterized by various competing ordering phenomena in the normal state, such as antiferromagnetism, charge order, orbital order or nematicity. According to a widespread view, antiferromagnetic fluctuations are the dominant ordering phenomenon in cuprates and Fe based superconductors and are responsible for electron pairing. In contrast, charge order is beli...

DESPI TE TWO DECADES OF IN TENSE RESEARCH , high temperature superconductors still hold many mysteries. Although they share some properties with their well-understood “conventional” low-temperature cousins, in particular the ability to carry current without any resistance, the differences are plentiful. The most obvious difference is the transition temperature TC, below which superconductivity ...

Normal superconductors with Rashba spin-orbit coupling have been explored as candidate systems of topological superconductors. Here we present a comparative theoretical study of the effects of different types of disorder on the topological phases of two-dimensional Rashba spin-orbit coupled superconductors. First, we show that a topologically trivial superconductor can be driven into a chiral t...

The elementary vortex pinning potential is studied in unconventional superconductors within the framework of the quasiclassical theory of superconductivity. Numerical results are presented for d-, anisotropic s-, and isotropic s-wave superconductors to show explicitly that in unconventional superconductors the vortex pinning potential is determined mainly by the loss of the condensation energy ...