DC Self-Field Critical Current in Superconductor/Dirac-Cone Material/Superconductor Junctions

• Main Author: Evgueni F. Talantsev
• Format: Article
• Language: English
• Published: MDPI AG 2019-11-01
• Series: Nanomaterials
• Subjects: the self-field critical current; induced superconductivity in dirac-cone materials; single layer graphene; multiple-band superconductivity
• Online Access: https://www.mdpi.com/2079-4991/9/11/1554

Recently, several research groups have reported on anomalous enhancement of the self-field critical currents, <i>I_c</i>(sf,<i>T</i>), at low temperatures in superconductor/Dirac-cone material/superconductor (S/DCM/S) junctions. Some papers attributed the enhancement to the low-energy Andreev bound states arising from winding of the electronic wave function around DCM. In this paper, <i>I_c</i>(sf,<i>T</i>) in S/DCM/S junctions have been analyzed by two approaches: modified Ambegaokar-Baratoff and ballistic Titov-Beenakker models. It is shown that the ballistic model, which is traditionally considered to be a basic model to describe <i>I_c</i>(sf,<i>T</i>) in S/DCM/S junctions, is an inadequate tool to analyze experimental data from these type of junctions, while Ambegaokar-Baratoff model, which is generally considered to be a model for <i>I_c</i>(sf,<i>T</i>) in superconductor/insulator/superconductor junctions, provides good experimental data description. Thus, there is a need to develop a new model for self-field critical currents in S/DCM/S systems.