»ã±¨±êÌâ (Title)£ºÂíÔ¼À­ÄÉÁãÄÜÄ£ºÍ¶à´øÌú»ù³¬µ¼ÌåÖеÄÍØÆËÁ¿×ÓÍÆË㣨Majorana zero modes and topological quantum computing in multi-band iron-based superconductors)

»ã±¨ÈË (Speaker)£ºÁõöÎ ½ÌÊÚ£¨ÉϺ£½»Í¨´óѧ£©

»ã±¨¹¦·ò (Time)£º2025Äê1ÔÂ3ÈÕ£¨ÖÜÎ壩9:30-10:00

»ã±¨µØÖ· (Place)£ºÐ£±¾²¿G601

Ô¼ÇëÈË(Inviter)£ºÖÓ½¨ÐÂ

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»ã±¨ÌáÒª£ºMajorana zero modes (MZMs) exhibit non-Abelian braiding statistics, rendering them a cornerstone for topological quantum computing. Experimentally feasible Majorana platforms require an extensive topologically non-trivial superconducting regime, a well-controlled ground-state degeneracy, and easy detection and manipulation of MZMs. In this talk, I will show that Majorana vortex states in iron-based superconducting nanowires fulfill these desirable conditions. We find that when the magnetic field is parallel to the [100] axis of FeSC, its multiband nature leads to two distinct topological phase diagrams: One comprises only trivial and topological superconducting phases, robust against multiband entanglement; The other one features alternating trivial, topological crystalline, and topological superconducting phases. Crucially, the former supports unpaired Majorana vortices over a broad range in parameter space, even with the Dirac nodes in electronic bands. The uniaxial strain can tune the transition between these two kinds of phase diagrams. As all the known FeSC nanowires are along the [100]-axis, we show the significant advantages of FeSC nanowires as a Majorana platform. At last, I will show that the iron-based superconductor nanowires can be compatible with the topological quantum computing schemes based on superconductor/semiconductor nanowires.

References:

[1] ¡°Anisotropic and tunable vortex topology in multiband iron-based superconductors¡±, Si-Qi Yu, Wei Cheng, Chuang Li, Xiao-Hong Pan, Gang Xu, Fu-Chun Zhang, and Xin Liu, arXiv:2412.19096 (2024)

[2] ¡°Controllable Majorana vortex states in iron-based superconducting nanowires¡±, Chuang Li, Xun-Jiang Luo, Li Chen, Dong E. Liu, Fu-Chun Zhang, and Xin Liu, National Science Review 9: nwac095 (2022)