TMC21: Superconducting proximity effect in topological insulator & superconductor hybrid structures скачать в хорошем качестве

TMC21: Superconducting proximity effect in topological insulator & superconductor hybrid structures

Topological Matter Conference (TMC) 2021: Superconducting proximity effect in topological insulator and superconductor hybrid structures Jiannong Wang, the Hong Kong University of Science and Technology Superconducting proximity effect in topological insulator and superconductor hybrid structure has attracted intense attention in recent years in an effort to search for mysterious Majorana fermions in condensed matter systems. Here I report on the superconducting proximity effect in a Bi2Se3/NbSe2 junction fabricated with an all-dry transfer method. Resulting from the highly transparent interface, two sharp resistance drops are observed at 7 K and 2 K, respectively, corresponding to the superconducting transition of NbSe2 flake and the superconducting proximity effect induced superconductivity in Bi2Se3 flake. Experimentally measured differential conductance spectra exhibit a bias-independent conductance plateau in the vicinity of zero bias below 7 K. As temperatures further decrease a zero bias conductance peak emerges from the plateau and becomes more enhanced and sharpened at lower temperatures. Our numerically simulated differential conductance spectra reproduce the observed bias-independent conductance p ateau and zero bias conductance peak and show that the superconducting proximity effect in topological surface states is much stronger than that in the bulk states of Bi2Se3. The Superconducting proximity effect induced superconducting gap for the topological surface states of Bi2Se3 is comparable to that of NbSe2 and gives rise to the observed bias-independent conductance plateau below 7 K. In contrast, the superconducting proximity effect induced superconducting gap for the bulk states of Bi2Se3 is an order of magnitude smaller than that of NbSe2 and superconducting topological surface states. These weakly paired bulk states in Bi2Se3 give rise to the zero bias conductance peak below 2 K. Our study has clearly unveiled the different roles of topological surface states and bulk stats in the superconducting proximity effect, clarified the physical origin of the induced features, and shined light on further investigation of superconducting proximity effect and Majorana fermion in topological insulator and supe conductor hybrid structures. --------------------------------------------------- The Topological Matter Conference (TMC) focuses on recent developments in fundamental and applied aspects of broad classes of topological quantum systems and the synergy between them. Topics include topological insulators and Weyl semimetals, topological phononics and photonics, skyrmions, quantum metrology and more. The TMC is a joint effort between the H2020 FET-PROACTIVE projects TOCHA (GA: 824140) and SKYTOP (GA: 824123) with the objective to establish synergies and to mobilize the Topological Matter community. Intended to lead to an annual gathering, the first TMC will be celebrated in 2021 from June 28th to July 2nd. If the pandemic situation allows it, the conference will be hosted at the Eden Roc hotel in Sant Feliu de Guixols, Spain, including Plenary, Invited, Oral and Poster contributions. Otherwise, the conference will be virtual, likely with no poster presentations. For more information: https://topologicalmatter.org/program/