Dimer structure as topological pinning center in a superconducting sample

Electronic structure and relaxation dynamics in a superconducting topological material

Topological superconductors host new states of quantum matter which show a pairing gap in the bulk and gapless surface states providing a platform to realize Majorana fermions. Recently, alkaline-earth metal Sr intercalated Bi2Se3 has been reported to show superconductivity with a Tc ~ 3 K and a large shielding fraction. Here we report systematic normal state electronic structure studies of Sr0...

Enhanced pinning in superconducting thin films with graded pinning landscapes

landscapes M. Motta, F. Colauto, W. A. Ortiz, J. Fritzsche, J. Cuppens, W. Gillijns, V. V. Moshchalkov, T. H. Johansen, A. Sanchez, and A. V. Silhanek Departamento de F ısica, Universidade Federal de S~ ao Carlos, 13565-905 S~ ao Carlos, SP, Brazil Department of Applied Physics, Chalmers University of Technology, S-412 96 G€ oteborg, Sweden INPAC – Institute for Nanoscale Physics and Chemistry,...

Pinning phenomena in a superconducting film with a square lattice of artificial pinning centers

We study the transport properties of a superconducting Nb film with a square lattice of artificial pinning centers (APCs) as a function of dc current, at a temperature close to the superconducting transition temperature of the film. We find that, at low dc currents, the differential resistance of the film shows the standard matching field anomaly, that is, the differential resistance has a loca...

Twin-boundary pinning of superconducting vortex arrays.

We discuss the low-temperature dynamics of magnetic flux lines in high-temperature superconductors in the presence of a family of parallel twin planes that contain the c axis. A current applied along the twin planes drives flux motion in the direction transverse to the planes and acts like an electric field applied to one-dimensional carriers in disordered semiconductors. As in flux arrays with...

Asymmetric Weak-Pinning Superconducting Channels: Vortex Ratchets