Stripe charge order and its interaction with Majorana bound states in 2M-WS2 topological superconductor

• Published in: National science review 2024-09
• Main Authors: Fan, Xuemin, Sun, Xiao-Qi, Zhu, Penghao, Fang, Yuqiang, Ju, Yongkang, Yuan, Yonghao, Yan, Jingming, Huang, Fuqiang, Hughes, Taylor L, Tang, Peizhe, Xue, Qi-Kun, Li, Wei
• Format: Article
• Language: English
• ISSN: 2095-5138; 2053-714X
• DOI: 10.1093/nsr/nwae312

To achieve logic operations via Majorana braiding, positional control of the Majorana bound states (MBSs) must be established. Here we report the observation of a striped surface charge order coexisting with superconductivity and its interaction with the MBS in the topological superconductor 2M-WS2 using low-temperature scanning tunneling microscopy. By applying an out-of-plane magnetic field, we observe that MBS is absent in vortices in the region with stripe order. This is in contrast to adjacent underlaying layers without charge order where vortex-bound MBSs are observed. Via theoretical simulations, we show that the surface stripe order does not destroy the bulk topology, but it can effectively modify the spatial distribution of MBSs, i.e., it pushes them downward away from the 2M-WS2 surface. Our findings demonstrate that the interplay of charge order and topological superconductivity can potentially be used to tune the positions of MBS, and to explore of new states of matter.