Место издания:Multiprint ( ООО ”ПКЦ АЛЬТЕКС” ) Moscow
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Последняя страница:17
Аннотация:Josephson junctions containing normal (N) and ferromagnetic (F) materials in
the weak link region are currently the subject of intense research. The interest in
such structures is due to the possibility of their use as a control elements of super-
conductor memory compatible with the RSFQ logic. At present there are many
implementations of such controls. Among them, the tunnel structures containing
oneferromagneticlayerintheweaklinkregionareofgreatestinterest. Anisotropy
of their properties necessary for operations is achieved in such devices by com-
plicating the structure of the weak-coupling area.
In this work we study theoretically the properties of S-F/N-sIS tunnel devices
in the frame of the quasiclassical Usadel formalism. We assume that the scale of
the structure is much less than the Josephson penetration depth. We demonstrate
that in the S-F/N-sIS device it is possible to achieve its separation into two regions
which have positive (0 segment) and negative (segment) critical current densi-
ties. We prove by numerical calculations that this separation is accompanied by a
new phenomenon, namely the violation of a spatial uniformity of the supercon-
ductive ilm and its decomposition into domains with an order parameter phase
diference equal to π. The efect is sensitive to thickness of the s layer and widths
of F and N ilms in the direction along the sIS interface and vanishes in the limit
of thick s-electrode.