Observation of Superconductivity Induced Ferromagnetism in an Fe-Chalcogenide Superconductor

TL;DR

This study uses nanoscale quantum sensing to reveal that superconductivity in FeTexSe1-x induces ferromagnetism, highlighting a coexistence that could enable new quantum phenomena and applications in quantum information technology.

Contribution

It provides the first nanoscale evidence of superconductivity-induced ferromagnetism in FeTexSe1-x, a topological superconductor, using NV center-based magnetic imaging.

Findings

Superconductivity induces ferromagnetism in FeTexSe1-x.

Nanoscale magnetic imaging confirms coexistence of superconductivity and ferromagnetism.

Potential for new quantum transport phenomena and quantum technology applications.

Abstract

The interplay among topology, superconductivity, and magnetism promises to bring a plethora of exotic and unintuitive behaviors in emergent quantum materials. The family of Fe-chalcogenide superconductors FeTexSe1-x are directly relevant in this context due to their intrinsic topological band structure, high-temperature superconductivity, and unconventional pairing symmetry. Despite enormous promise and expectation, the local magnetic properties of FeTexSe1-x remain largely unexplored, which prevents a comprehensive understanding of their underlying material properties. Exploiting nitrogen vacancy (NV) centers in diamond, here we report nanoscale quantum sensing and imaging of magnetic flux generated by exfoliated FeTexSe1-x flakes, providing clear evidence of superconductivity-induced ferromagnetism in FeTexSe1-x. The coexistence of superconductivity and ferromagnetism in an established topological superconductor opens up new opportunities for exploring exotic spin and charge transport phenomena in quantum materials. The demonstrated coupling between NV centers and FeTexSe1-x may also find applications in developing hybrid architectures for next-generation, solid-state-based quantum information technologies.