The long-sought yet elusive Majorana fermion is predicted to arise from a combination of a superconductor and a topological insulator. An essential step in the hunt for this emergent particle is the unequivocal observation of supercurrent in a topological phase. Here, direct evidence for Josephson supercurrents in superconductor (Nb)-topological insulator (Bi(2)Te(3))-superconductor electron-be...

Surface atomic-layer (SAL) superconductors consisting of epitaxially grown metal adatoms on a clean semiconductor surface have been recently established. Compared to conventional metal thin films, they have two important features: (i) space-inversion symmetry-breaking throughout the system and (ii) high sensitivity to surface adsorption of foreign species. These potentially lead to manifestatio...

In this laboratory work we will study the vortex lattice VL of a type II superconductor using Small Angle Neutron Scattering SANS. The sample is a single crystal of Nb, a superconductor with a Tc = 9.3 K and lower and upper critical fields of μ0Hc1 = 0.18T and μ0Hc2 = 0.4T, respectively. For external magnetic fields between Hc1 and Hc2 the superconductor is in the so-called intermediate state. ...

Abstract: The world-line formalism is used for the evaluation of the mixed heavy-quark– gluon condensate in two models of QCD – the stochastic vacuum model and the dual superconductor one. Calculations are performed for an arbitrary dimensionality of spacetime d ≥ 2. While in the stochastic vacuum model, the condensate is UV finite up to d = 8, in the dual superconductor model it is UV divergen...

We study theoretically the electronic and transport properties of a diffusive superconductor-normal metal-superconductor (SNS) junction in the presence of a perpendicular magnetic field. We show that the field dependence of the critical current crosses over from the well-known Fraunhofer pattern in wide junctions to a monotonic decay when the width of the normal wire is smaller than the magneti...

Crucially important for application of type-II superconductor films is the stability of the vortex matter--magnetic flux lines penetrating the material. If some vortices get detached from pinning centres, the energy dissipated by their motion will facilitate further depinning, and may trigger a massive electromagnetic breakdown. Up to now, the time-resolved behaviour of these ultra-fast events ...

The transport properties of a ferromagnet–superconductor (FS) junction are studied in a scattering formulation. Andreev reflection at the FS interface is strongly affected by the exchange interaction in the ferromagnet. The conductance GFS of a ballistic point contact between F and S can be both larger or smaller than the value GFN with the superconductor in the normal state, depending on the r...

Superconductor–ferromagnet–superconductor (SFS) Josephson junctions are known to exhibit a transition between π and 0 states. In this letter, we find the π–0 phase diagram of an SFS junction depending on the transparency of an intermediate insulating layer (I). We show that, in general, the Josephson critical current is nonzero at the π–0 transition temperature. Contributions to the current fro...