We study a realistic Floquet topological superconductor, periodically driven nanowire proximitized to an equilibrium s-wave superconductor. Because of the strong energy and density fluctuations caused by superconducting proximity effect, Majorana wire becomes dissipative. show that band structure is still preserved in this dissipative system. In particular, we find zero $\ensuremath{\pi}$ modes...

We use large-scale Monte-Carlo simulations to study thermal fluctuations in chiral $p$-wave superconductors an applied magnetic field three dimensions. consider the stability of previously predicted unusual double-quanta flux-line lattice ground states such superconductors. In previous works it was shown that, neglecting fluctuations, a superconductor forms hexagonal doubly-quantized vortices, ...

As the normal state sheet resistance, Rn, of a thin film superconductor increases, its superconducting properties degrade. For Rn ≃ h/4e superconductivity disappears and a transition to a nonsuperconducting state occurs. We present electron tunneling and transport measurements on ultrathin, homogeneously disordered superconducting films in the vicinity of this transition. The data provide stron...

Using the negative U Hubbard model we analyze normal state properties of a superconductor. In this model there exists a characteristic pairing temperature TP above a superconducting critical temperature. Below TP electrons start to form incoherent pairs. The fluctuations in charge and phase are precursors of charge density wave and superconductivity phases depending on band filling. They lead n...

We study a diffusive superconductor-normal-metal-superconductor junction in an environment with intrinsic incoherent fluctuations which couple to the junction through an electromagnetic field. When the temperature of the junction differs from that of the environment, this coupling leads to an energy transfer between the two systems, taking the junction out of equilibrium. We describe this effec...

We investigate the mechanism by which topological defects form in first order phase transitions with a charged order parameter. We show how thick superconductor vortices and heavy cosmic strings form by trapping of magnetic flux. In an external magnetic field, intermediate objects such as strips and membranes of magnetic flux and chains of single winding defects are produced. At non-zero temper...

We report spin-dependent electron density of states (DOS) studies of ultrathin superconducting Al and Be films in high parallel magnetic fields. Superconductor-insulator-superconductor (SIS) tunneling spectra are presented in which both the film and the counterelectrode are in the paramagnetic limit. This SIS configuration is exquisitely sensitive to spin mixing and/or spin flip processes which...

When a tunneling barrier between two superconductors is formed by a normal material that would be a superconductor in the absence of phase fluctuations, the resulting Josephson effect can undergo an enormous enhancement. We establish this novel proximity effect by a general argument as well as a numerical simulation and argue that it may underlie recent experimental observations of the giant pr...

For the first time for a cuprate superconductor, measurements performed above T(c) in high quality grain aligned La1.9Sr0.1CuO4 samples have allowed the observation of the thermal fluctuation induced diamagnetism well inside the finite-magnetic-field fluctuation regime. These results may be explained in terms of the Gaussian Ginzburg-Landau approach for layered superconductors, but only if the ...

In order to investigate the origin of the until now unaccounted excess noise and to minimize the uncontrollable phenomena at the transition in X-ray mi-crocalorimeters we have developed superconducting transition-edge sensors into an edgeless geometry, the so-called Corbino disk (CorTES), with super-conducting contacts in the centre and at the outer perimeter. The measured rms current noise and...