Joint work of ML4Q members Mussler, Schüffelgen, Grützmacher and Schäpers at Forschungszentrum Jülich was recently published in Nanomaterials. The publication reports on results obtained in a study of the properties of superconductivity induced into a topological material in terms of direct current, radio frequency irradiation and the effect of magnetic fields. The findings include the agreement between simulation and experiment which indicates that the in-situ nano fabrication is a promising platform for complex superconducting networks. Furthermore, the observation of a fractional Shapiro step supports that topological materials may add rich physics to the multi terminal dynamics.
Rendering of a selective-area grown three-terminal Josephson junction and false color scanning electron micrograph with circuit: (a) The three-terminal junction is composed of the silicon substrate (gray bottom layer), the first hard mask composed out of a silicon oxide (white)/silicon nitride (blue) layer (as indicated by the labels). On top of this, another hard mask layer composed of silicon oxide (white) and silicon nitride (blue) is deposited and patterned as a shadow mask. The topological insulator (red) is grown selectively into the first hard mask trench and the shadow mask is used for the definition of the junction in the metal deposition (silver) step. (b) False-color scanning electron micrograph of the in situ prepared three-terminal junction device. Niobium contacts (cyan) are deposited on top of the TI (red). The measurement configuration is also indicated. [Source: MDPI, Figure 1 of the publication]
Publication: J. Kölzer, A. R. Jalil, D. Rosenbach, L. Arndt, G. Mussler, P. Schueffelgen, D. Grützmacher, H. Lüth, and Th. Schäpers, Supercurrent in BiTe Topological Material-Based Three-Terminal Junctions, Nanomaterials 13, 2: 293 (2023)
https://www.mdpi.com/2079-4991/13/2/293#
UPDATE: In March, the study was awarded editor’s choice at MDPI Nanomaterials. Congratulations to all the authors!