We have studied mesoscopic Josephson junctions formed by highly n-doped InAs nanowires and superconducting Ti/Pb source and drain leads. The current-voltage properties of the system are investigated by varying temperature and external out-of-plane magnetic field. Superconductivity in the Pb electrodes persists up to ∼7 K and with magnetic field values up to 0.4 T. Josephson coupling at zero bac...

A theory of the de Haas–van Alphen effect in type-II p-wave and D-wave superconductors ~the latter corresponds to the B1g one-dimensional representation of group D4h) has been developed. Solutions for the order parameter and density of quasiparticle states near the upper critical field have been calculated. If the curve enclosing the extremal cross section of the Fermi surface in the plane perp...

Epitaxial Ho/Nb/Ho and Dy/Nb/Dy superconducting spin valves show a reversible change in the zero-field critical temperature (ΔT(c0)) of ∼400  mK and an infinite magnetoresistance on changing the relative magnetization of the Ho or Dy layers. Unlike transition-metal superconducting spin valves, which show much smaller ΔT(c0) values, our results can be quantitatively modeled. However, the fits re...

We report on flux confinement effects in superconducting submicron line, loop and dot structures. The main idea of our study was to vary the boundary conditions for confinement of the superconducting condensate by taking samples of different topology and, through that, modifying the lowest Landau level ELLL(H). Since the critical temperature versus applied magnetic field Tc(H) is, in fact, ELLL...

The influence of a Zeeman magnetic field on the superconducting characteristics of the attractive Hubbard model has been investigated. The ground state and temperature phase diagrams have been obtained for a fixed number of particles. Two critical magnetic fields have been found for the first order phase transition from the superconducting (SC) to the normal (NO) state for n 6= 1. For some rang...

High-quality single crystals of Lu2Fe3Si5 and Sc2Fe3Si5 are grown by the floatingzone method, and their temperature dependences of specific heat are measured down to 0.35 K. Both compounds show anomalously small jump in specific heat at the superconducting transition temperature, Tc, and large residual specific heat coefficient even at 0.2Tc, where BCS superconductor shows negligible electronic...

For any practical superconductor the magnitude of the critical current density, Jc, is crucially important. It sets the upper limit for current in the conductor. Usually Jc falls rapidly with increasing external magnetic field, but even in zero external field the current flowing in the conductor generates a self-field that limits Jc. Here we show for thin films of thickness less than the London...

Grain boundaries are extensively used as high-quality Josephson junctions in high-Tc superconductors. Their superconducting characteristics can generally be well described by conventional models of strongly coupled Josephson junctions. Here, we report on highly anomalous critical current vs. magnetic field dependencies of grain boundaries in YBa2Cu307-,. Direct imaging with scanning SQUID micro...