arXiv subjects

A. Rusanov

Publications and source records attributed to A. Rusanov.

2 recordsLinked to original sources

arXiv2003

Depairing currents in superconductor / ferromagnet Nb/CuNi trilayers close to T$_c$

In superconductor/ferromagnet (S/F) heterostructures, the exchange field $h_{ex}$ 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 $h_{ex}$, on the superconductivity. We used a pulsed-current technique in order to measure the superconducting transport properties of Cu$_{1-x}$Ni$_x$/Nb/Cu$_{1-x}$Ni$_x$ ($x$ = 0.54) F/S/F trilayers structured in strips of about 2 $μ$m wide and 20 $μ$m long as function of a small in-plane magnetic field. We find that the depairing current is tied to the magnetization behavior. In particular, we show that the suppression of superconductivity in the S-layer is smallest when the external magnetic field equals the coercive field H$_{c}$ of the F-layers.

cond-mat.supr-con↗

arXiv2001

Inhomogeneous superconductivity induced in a weak ferromagnet

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 pi-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.

cond-mat.supr-con↗