Critical currents in bulk composites

Current–voltage characteristics of break junctions of high-Tc superconductors

“…According to the KGN model, the hysteretic peculiarity reflects a part of I-V curve with a negative differential resistance which can be observed under bias voltage [11,12]. The KGN approach was used earlier to the description of experimental I-V curves of low-T c [13,14] and high-T c weak links [15,13].…”

“…Also we have used Eq. (2) to estimate the number of resistive weak links in the sample of composite 92.5 vol.% YBCO + 7.5 vol.% BaPbO 3 [15]. The I-V curve of this composite was described earlier by the KGN based approaches [15,13].…”

The effect of paramagnetic impurities in normal metal on the critical current in a network of S N S Josephson junctions in bulk Y3/4Lu1/4Ba2Cu3O7 BaPb1 xFexO3composites

“…On the other hand, HTSC-based composites are a typical example of a weak-link network with a non-superconducting component playing the role of barriers separating the HTSC crystallites [21][22][23][24][25][26][27][28][29][30][31]. Although the transport properties of such composites are affected by the distribution function of the geometrical parameters of the nonsuperconducting layers [32], nevertheless, the main features of the resistive state of the composites remain the same as those of some single weak links [24,26,28,31].…”

“…On the other hand, HTSC-based composites are a typical example of a weak-link network with a non-superconducting component playing the role of barriers separating the HTSC crystallites [21][22][23][24][25][26][27][28][29][30][31]. Although the transport properties of such composites are affected by the distribution function of the geometrical parameters of the nonsuperconducting layers [32], nevertheless, the main features of the resistive state of the composites remain the same as those of some single weak links [24,26,28,31]. For example, the HTSC + insulator composites prepared by us [28] demonstrate current-voltage (I −V ) characteristics having excess voltage, and a broad resistive transition is successfully described by the mechanism of thermally activated phase slippage [33], developed for SIS (where I is insulator) structures.…”

Proximity effect, Andreev reflections, and charge transport in mesoscopic superconducting/semiconducting heterostructures

“…The electrons are either in the inversion layer which forms between p-InAs and Niobium (Nb) [4,5,6], or they accumulate in MBEgrown quantum wells formed by n-type InAs between a p-type InAs buffer layer [7], see also [8], or an AlSb substrate and two [7,9,10,11] or up to 300 [10,12] Nb electrodes, separated by insulating AlSb layers. -Transport properties of SSmS and SNS junctions involving high-temperature superconductors are investigated, too [13,14].…”