Josephson-coupled layered superconductors with two order parameters. II. Lower critical magnetic field

1994 ◽  
Vol 6 (11) ◽  
pp. 2259-2268 ◽  
Author(s):  
E P Nakhmedov ◽  
E V Tahirov
1995 ◽  
Vol 8 (5) ◽  
pp. 601-602
Author(s):  
Yu. N. Ovchinnikov ◽  
V. Z. Kresin

1995 ◽  
Vol 52 (5) ◽  
pp. 3075-3078 ◽  
Author(s):  
Yu. N. Ovchinnikov ◽  
Vladimir Z. Kresin

Fractals ◽  
1997 ◽  
Vol 05 (supp02) ◽  
pp. 101-117
Author(s):  
A. S. Sidorenko

The influence of fractal geometry on superconductivity has been studied for layered superconductors. Superconducting multilayers consisting of alternating Nb and Cu layers with fractal stacking sequence and fractal dimension Df=0.63 including the two limiting cases Df= 0 (single superconducting film) and Df=1 (periodic multilayers) were prepared by electron-beam evaporation in ultrahigh vacuum. The layers of Nb and Cu were put down alternately via computer control of the target shutter. The structure of the samples has been checked with in situ reflection high-energy electron diffraction (RHEED) and Auger depth profiling, confirmed the prescribed layering geometry. Superconductivity was investigated by measurements of the critical temperature of superconducting transition Tc, and of the temperature and of the angular dependence of the upper critical magnetic fields Bc2. The observed dependences of Tc on the parameters of fractal samples are in a good qualitative agreement with the proximity effect theory developed for layered superconductors with a self-similar fractal structure. The behavior of the upper critical magnetic field is directly related to the type of the layering. At low temperatures, all samples show the same two-dimensional behavior essentially governed by the topological dimension of the individual superconducting layers, independent of the fractal dimensionality Df of the samples, whereas for temperatures near Tc the type of layering determines the dimensionality, resulting in a multicrossover behavior of fractal samples. The angular dependence of the upper critical magnetic field Bc2(θ) of fractals corresponds to the theory for a two-dimensional superconductor at all temperatures, reflecting the multicrossover behavior of the fractal multilayers, as long as the temperature-dependent coherence length is comparable with a certain scale of fractal.


2021 ◽  
Vol 103 (8) ◽  
Author(s):  
Fumikazu Oguro ◽  
Yudai Sato ◽  
Kanta Asakawa ◽  
Masahiro Haze ◽  
Yukio Hasegawa

1966 ◽  
Vol 150 (1) ◽  
pp. 222-225 ◽  
Author(s):  
Rudolf Klein ◽  
Gaston Fischer

1985 ◽  
Vol 54 (5) ◽  
pp. 477-480 ◽  
Author(s):  
M. B. Maple ◽  
J. W. Chen ◽  
S. E. Lambert ◽  
Z. Fisk ◽  
J. L. Smith ◽  
...  

2016 ◽  
Vol 30 (25) ◽  
pp. 1650183 ◽  
Author(s):  
Yu. N. Ovchinnikov

The effect of spin-orbit (SO) interaction on the formation of the critical states in thin superconducting films in magnetic field oriented along the film is investigated. Hereby, the case of interband pairing is considered. It was found that eight branches exist in the plane of two parameters [Formula: see text] determined by the value of magnetic field and SO interaction. Six modes leads to inhomogeneous states with different values of the impulse [Formula: see text]. Each state is doubly degenerate over direction of impulse [Formula: see text]. The parameter values at critical point are found for all eight branches in explicit form for zero temperature. The optimal two branches are estimated, corresponding to largest critical magnetic field value for given SO interaction.


Sign in / Sign up

Export Citation Format

Share Document