Alexander Yu. Rusanov

Enhancement of the superconducting transition temperature in Nb/permalloy bilayers by controlling the domain state of the ferromagnet.

In (S/F) hybrids the suppression of superconductivity by the exchange field h(ex) of the ferromagnet can be partially lifted when different directions of h(ex) are sampled simultaneously by the Cooper pair. In F/S/F trilayers where the magnetization directions of the F layers can be controlled separately, this leads to the so-called spin switch. Here we show that domain walls in a single F layer yield a similar effect. We study the transport properties of Ni(0.80)Fe(0.20)/Nb bilayers structured in strips of different sizes. For large samples a clear enhancement of superconductivity takes place in the resistive transition, in the very narrow field range (order of 0.5 mT) where the magnetization of the Py layer switches and many domains are present. This effect is absent in microstructured samples.

Supercurrents through the superconductor–ferromagnet–superconductor (SFS) junctions

Abstract We have observed and studied critical supercurrents, I c , in cross-type Nb–Cu/Ni–Nb junctions with Josephson layers prepared from diluted ferromagnetic alloys. For suitable values of the exchange energy in the ferromagnet and the F-layer thickness we have observed I c ( T ) oscillation with vanishing I c for definite values of T and d F .

Inhomogeneous superconductivity induced in a weak ferromagnet

Abstract Under certain conditions, the order parameter induced by a superconductor (S) in a ferromagnet (F) can be inhomogeneous and oscillating, which results e.g. in the so-called π -coupling in S/F/S junctions. In principle, the inhomogeneous state can be induced at T c as function of the F-layer thickness d F in S/F bilayers and multilayers, which should result in a dip-like characteristic of T c ( d F ). We show the results of measurements on the S/F system Nb/Cu 1− x Ni x , for Ni-concentrations in the range x =0.5–0.7, where such effects might be expected. We find that the critical thickness for the occurrence of superconductivity is still relatively high, even for these weak ferromagnets. The resulting dip then is intrinsically shallow and difficult to observe, which explains the lack of a clear signature in the T c ( d F ) data.

Depairing currents in superconductor ferromagnet Nb/CuNi trilayers close to Tc

In superconductor/ferromagnet (S/F) heterostructures, the exchange field

Mesoscopic Models of Plants Composed of Metallic Nanowires

h_{ex}

Coupling of Two Superconductors through a Ferromagnet

of the F-layer suppresses the superconducting order parameter in the S-layer via the proximity effect. One issue in current research is the effect of a domain state, or, more generally, different directions of

Depairing current behavior in superconducting Nb/Pd81Ni19 bilayers

h_{ex}

The effects of magnetization switching on the superconducting properties of S/F bilayers and F/S/F trilayers

, on the superconductivity. We used a pulsed-current technique in order to measure the superconducting transport properties of Cu

With no Color and Scent: Nanoflowers of Metals and Alloys

_{1-x}

Second-Harmonic Current-Phase Relation in Josephson Junctions with Ferromagnetic Barriers

Ni