2024/06/11 by Sangyun Lee, Lee, Sangyun, Myungjun Kang +11
Materials Science · Physics and Astronomy · #Advanced Chemical Physics Studies #FOS: Physical sciences #Iron-based superconductors research #Superconductivity (cond-mat.supr-con) #Topological Materials and Phenomena
paper · pdf · doi:10.48550/arxiv.2406.07260
openalex publication_date 2024/06/11 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Exploration of nontrivial superconductivity and electronic band topology is at the core of condensed matter physics and applications to quantum information. The transition-metal dichalcogenide (TMDC) MoTe2 has been proposed as an ideal candidate to explore the interplay between topology and superconductivity, but their studies remain limited regarding the required high-pressure environments. Here, we observe proximity-induced surface p-wave superconductivity, and investigate the higher-order topological nature of MoTe2 in its 1T' phase, which emerges from the Td phase through a high-pressure-induced topological phase transition. Using surface-sensitive soft-point-contact Andreev reflection spectroscopy, we confirm the emergence of surface s+p-wave superconductivity via the BTK model as well as a zero-bias conductance peak. Such surface p-wave superconductivity emerges via the proximity effect between an s-wave superconducting band and a second-order topological band, which is protected by the time-reversal and inversion symmetries. The temperature dependence of the surface p-wave superconducting gap shows a correlation with that of the bulk s-wave gap, as well as its suppression by an external magnetic field or a reduction in pressure, implying its proximity-induced origin. Moreover, we suggest that the topological hinge states, derived from second-order topological bands, evolve into zero-energy Majorana corner states in this proximity-effect-induced third-order topological superconducting phase. These results demonstrate the potential realization of topological superconductivity in MoTe2, thus opening a pathway for studying various topological natures of TMDC materials.