Analysis of Internally Shunted Josephson Junctions

Abstract

Following the ever-rising demand for new functionalities and novel materials in superconducting circuitry, we provide a complete view on the self-shunting problem in Josephson junctions relating it to specific features of a multichannel weak link between electrodes where averaging over the channels yields a bimodal distribution of transparencies with maxima near unity and zero. We provide two examples of such internally-shunted devices, four-layered Nb/Al-Al oxide-Nb junctions with strongly disordered nm-thick insulating layers where stochastic distribution of transparencies takes place on a local rather than a global scale and MoRe/W-doped Si-Si-MoRe devices with strongly inhomogeneous silicon interlayers partly doped by metallic nanoclusters where the main charge transport occurs across resonance-percolating trajectories. We show how the predicted universal distribution function of transmission coefficients can be verified experimentally without any fitting parameters and analyze some old and new experimental data from this perspective. We believe that our results can form a base for novel four-layered Josephson junctions with enhanced superconducting properties and, at the same time, well-separated metallic electrodes.

Dissipation effects in superconducting heterostructures with tungsten nanorods as weak links

“…24 the appearance of phase difference by 2π over the nanowire is the dual process to Cooper-pair tunneling in a Josephson junction and hence, by analogy to the Josephson voltage standard, a quantum phase-slip device can realize the fundamental current standard. We hope that the Josephson heterostructures with strongly disordered weak-link interspace proposed in our previous works [4,7,25] and developed in this paper can be used as a prototype of such quantum devices.…”

Intrinsically shunted Josephson junctions for electronics applications

“…3 In the right inset in Fig. 3 we present theoretical expectations [56] and related experimental data for five superconductive junctions formed by superconducting MoRe-alloy electrodes and a several tens nm thick Si interlayer doped by tungsten [62]. From the comparison in Fig.…”

“…The agreement is good (most probably, superconducting correlations induced in the Al interlayer due to the proximity to a Nb electrode are weaker than those predicted in the dirty limit). [56]), and S/N-I-S (dirty limit with proximity-effect account [53]), respectively.…”

“…Then the main proximity-induced changes are originated from the Andreev reflections at the S/N interface accompanied by phase shifts arisen from electron (a hole) passages across the N layer. A final mean free path in the Al film caused by impurity scatterings can be introduced into this scheme, as explained in Ref 56…”

Negative $N$-Type Differential Resistance in Current–Voltage Characteristics of Metal Heterostructures

“…Что касается экспериментальной реализации обсуждаемого эффекта, то, по нашему мнению, наиболее перспективными объектами такого рода могут быть двухбарьерные джозефсоновские гетероструктуры, реализованные, в частности, в работе [11]. При этом в качестве сверхпроводниковых обкладок следует использовать соединения с переходными металлами, которые обладают хорошей поверхностью и достаточно высокими температурами сверхпроводящего перехода, например, NbN [12] или MoRe [13,14].…”