Work

Multiband-driven anisotropic vortex topology in iron-based superconductors yielding a strain-tunable x-vortex Majorana platform

Year: 2026

Type: article

Abstract: We uncover a pronounced anisotropy in Majorana vortex topology arising from the interaction between vortex orientation and multiband topologies, exemplified by iron-based superconductors (FeSCs). This anisotropy manifests in two distinct vortex configurations: the z-vortex and x-vortex, oriented perpendicular and parallel to the Dirac axis (z-axis for FeSCs), respectively. The x-vortex exhibits a unique bifurcation, displaying two distinct topological phase diagrams. One is strikingly simple, comprising only trivial and topological superconducting phases, and remains resilient to multiband entanglement. The other mirrors the z-vortex’s complex diagram, featuring alternating trivial, topological crystalline, and topological superconducting phases. The former is exclusive to the x-vortex and supports unpaired Majorana vortices across a wide parameter range, even in the presence of normal-state Dirac nodes. Notably, uniaxial strain can modulate these x-vortex phases, enabling the x-vortex to support both stable Majorana vortices and rich exotic physics in a controllable manner. Moreover, we propose that the x-vortex offers promising advantages for developing Majorana nanowire devices in FeSCs. Our findings introduce a novel paradigm in vortex topology within multiband superconducting systems, highlighting the x-vortex as a promising platform for exploring Majorana physics and advancing FeSC quantum devices. Previous studies of vortex Majorana zero modes (MZMs) in iron-based superconductors have predominantly considered the case where magnetic field is parallel to the Dirac axis. Here, the authors focus on vortices oriented perpendicular to the Dirac axis, finding that such vortices are more favorable for observing vortex MZMs.

Source: Nature Communications

DOI: 10.1038/s41467-026-71938-3