Michał Nowak (27.02, 17:00)
Affiliation: AGH University of Science and Technology, Poland Title: Multiple Andreev reflections: characterization of hybrid nanostructures and novel supercurrent Abstract:Under application of a voltage bias to a superconductor-semiconductor-superconductor junction sequential Andreev reflections on the superconducting contacts result in a dc-current whose magnitude is a non-linear function of the junction transparency and the number of current-carrying modes. We exploit this phenomenon to demonstrate few-mode current transport in InSb [1] and Ga-Si core-shell nanowires [2] favorable for creating topological superconductivity. Finally, we show that in a multiterminal junction the DC-current consists of supercurrent components when the bias voltages are commensurate despite the absence of bound-states that carry disspationless current [3]. [1] Ö. Gül, H. Zhang, F. K. de Vries, J. van Veen, K. Zuo, V. Mourik, S. Conesa-Boj, M. P. Nowak, D. J. van Woerkom , M. Quintero-Pérez, M. C. Cassidy, A. Geresdi, S. Kölling, D. Car, S. R. Plissard, E. P.A.M. Bakkers, L. P. Kouwenhovenn, Nano. Lett., 17, 2690 (2017). [2] F. K. de Vries, J. Shen, R. J. Skolasinski, M. P. Nowak, D. Varjas, L. Wang, M. Wimmer, J. Ridderbos, F. A. Zwanenburg, A. Li, S. Koelling, M. A. Verheijen, E. P. A. M. Bakkers, L. P. Kouwenhoven, Nano Lett. 18, 6483 (2018). [3] M. P. Nowak, M. Wimmer, A. R. Akhmerov, arXiv:1811.00916 (2018).