The new form of the composite operator generalizing the Cooper pairs for a BCS superconductor is introduced. The approach is similar to the derivation of the composite operator of the odd-frequency superconductors. The examples of the d x 2 −y 2 −, d xy − and p− wave composite operators for a 2D t − J model are given.

The critical state stability in a composite superconductor under an external stress, causing plastic strain yield, is considered. The obtained criterion of the stability against thermomagnetic-mechanical perturbations allows the explanation of the training phenomenon as a process of consequent strain hardening of the superconductor. The training of superconducting materials is a well known phen...

We study the dynamics of normal domains in a multifilamentary composite superconductor with a large amount of stabilizer outside the multifilamentary area. We consider the case when there is a transition layer with high thermal and electrical resistance between the superconductor and the stabilizer. We show the existence of localized and propagating normal domains in these composites. We derive...

We review and extend some results for a generalized Ginzburg-Landau energy functional, introduced in the physics literature to model composite superconducting/normal body. In this formulation, the order parameter is defined everywhere in the composite system, with the intention to capture the effect of superconducting electrons pairs diffusing in the normal parts. For suitable choices of the ma...

The current distribution and the AC loss in a composite superconducting tape containing a layer from magnetic material is calculated and compared with experiments, showing a very good agreement. The situations of an alternating uniform applied field or a transport current are studied. The newly developed numerical model is an approximation to the critical state model, adapted for the applicabil...

We investigated how a 10–50 μm layer from soft ferromagnetic material, incorporated in the architecture of a composite superconducting tape, could influence the capability of the tape to transport electrical current. Numerical procedure was developed to calculate the local distribution of magnetic field and current in the condition when all the superconductor is carrying its critical current de...

Nanorod/superconductor composites were formed by depositing Tl2Ba2Ca2Cu3Oz ~Tl-2223! thick films on high density MgO nanorod arrays that were grown on MgO single crystal substrates. Electron microscopy studies show that this approach creates a high density of columnar defects normal to the CuO2 planes within crystal grains of the composites. The nanorod/superconductor composites exhibited enhan...

The Pfaffian phase in the proximity of a half-filled Landau level is understood to be a p+ip superconductor of composite fermions. We consider the properties of this paired quantum Hall phase when the pairing energy is small, i.e., in the weak-coupling, BCS limit, where the coherence length is much larger than the charge screening length. We find that, as in a type I superconductor, vortices at...

Transport properties of a superconductor-semiconductor-superconductor (Su-Sm-Su) junction with superlattice structure are investigated. Differential resistance as a function of voltage shows oscillatory behavior under the irradiation of radio-frequency (rf) waves with the specific frequency of 1.77 GHz regardless of the superconducting materials and the junction geometries. Experimental data ar...

A new class of superconductors with the gap function odd under time reversal is considered. Some of the physical properties of these superconductors such as the Meissner effect, composite condensate, gapless spectrum and transition from the odd gap superconductor to the BCS state at lower temperatures are discussed.