Solitary Superconductivity Research Articles

How experimentally to detect a solitary superconductivity in dirty ferromagnet-superconductor trilayers?

We theoretically study the proximity effect in the thin-film layered ferromagnet (F) – superconductor (S) heterostructures in F1F2S design. We consider the boundary value problem for the Usadel-like equations in the case of so-called “dirty” limit. The “latent” superconducting pairing interaction in F layers taken into account. The focus is on the recipe of experimental preparation the state with so-called solitary superconductivity. We also propose and discuss the model of the superconducting spin valve based on F1F2S trilayers in solitary superconductivity regime.

The Solitary Superconductivity in Dirty F $$ _1 $$ 1 F $$ _2 $$ 2 S Trilayer with Arbitrary Interfaces

We theoretically study the proximity effect in ferromagnet–superconductor trilayer in the F\(_1\)F\(_2\)S design. Electron–electron pairing interaction in F layers is taken into account. The boundary value problem is considered in the frame of Usadel equations. The conditions of the solitary superconductivity appearance in F\(_1\)F\(_2\)S system are theoretically investigated taking into account of arbitrary transparencies of interfaces. The experimental observation of this effect and its spin-valve application are discussed.

Solitary superconductivity in a ferromagnet–superconductor heterostructure

A ferromagnet (F)–superconductor (S) (F1F2S) three-layer heterostructure has been studied using Usadel equations with allowance for the pair electron–electron interaction in ferromagnetic layers. The appearance of regions with solitary superconductivity on the phase diagram has been predicted for the antiparallel configuration of the magnetization in F layers. Conditions for the possible experimental observation of solitary superconductivity in FFS three-layer structures, as well as for the detection of the electron–electron interaction in ferromagnets, have been discussed.

A Manifestation of Latent Superconductivity in Ferromagnet via a Proximity Effect in FS Structures

We theoretically study the proximity effect in the thin-film layered ferromagnet (F) - super-conductor (S) heterostructures of two types (F1SF2 and F1F2S). We consider the boundary value problem for the Usadel-like equations in the case of so-called “dirty” limit. The “latent” superconducting pairing interaction in F layers taken into account. It is shown that the inter-electronic interaction essentially influences on the critical properties of the both trilayers. The appearance of the solitary superconductivity is predicted for the F1SF2 and F1F2S systems.

A solitary superconductivity in layered ferromagnet-superconductor heterostructures

An electron-electron interaction in a ferromagnet (F) was neglected in the standard approach to the proximity effect theories for the layered FS structures (here S is used for a superconductor). Actually this interaction exists, but it is suppressed by strong exchange field and can reveal itself if an exchange fields of adjacent F layers compensate each other. In the clean FS structures limit the preceding consideration of this interaction could explain a surprisingly high critical temperature Tc in the short-periodic Gd/La superlattice. Here we analyze this problem for dirty case based on the Usadel equations solutions changing parameters of asymmetrical FS systems (thicknesses of layers, boundary transparencies, etc). Taking into account an electron-electron interaction leads to an appearance of hidden superconductivity of F layers which can manifest itself in the proximity effect conditions. It is especially expressed if magnetizations in F layers have opposite signs. The solitary superconductivity is also predicted for asymmetrical dirty FSF trilayers.

The spin valve device based on asymmetrical ferromagnet-superconductor trilayer in an external magnetic field

We theoretically explore superconducting proximity effect for the three-layered ferromagnet/superconductor (FS) heterostructures. We consider the boundary value problem for the Usadel-like equations in the case of so-called "dirty" limit. The different mutual orientations of the F layers magnetizations are examined in presence of the external magnetic field. The results of numerical calculations for critical temperature Tc at various parameters of FS structures are presented. The appearance of solitary superconductivity is predicted for the F1F2S system. We also discuss possible spin valve applications for F1F2S trilayers.

Interelectronic interaction in dirty FS trilayers: A manifestation of “hidden” superconductivity

The properties of the ferromagnet/superconductor (FS) system are theoretically studied. Electron–electron pairing interaction in F layers is taken into account. The boundary value problem for the Usadel-like equations is considered in the case of so-called “dirty” limit. It is shown that both asymmetry and interelectronic interaction essentially influence on the critical properties of the F1SF2 trilayer. The appearance of the solitary superconductivity is predicted for this asymmetrical trilayer.

A Peculiar Solitary Re-entrant Superconductivity Induced by an External Magnetic Field in Ferromagnet-Superconductor Heterostructures

We solve the boundary value problem for the Usadel-like equations in the dirty limit case for thin-film three-layered ferromagnet (F) - superconductor (S) structures. Our theoretical approach taking into account of the asymmetry and triplet superconducting correlations is valid in the external magnetic field presence as in the real experimental setup for the FS spin valve explorations. Based on the recent experimental data obtained for the symmetrical (FSF) trilayer in an external magnetic field, we expand the theoretical description to the asymmetrical FSF and FFS trilayers. We also consider the peculiar re-entrant superconductivity and solitary superconductivity induced by the external magnetic field for the FFS trilayer.