2019Journal of Physics: Condensed Matter

Quasi-2D superconductivity in FeTe₀.₅₅Se₀.₄₅ ultrathin film

Fangdong Tang, Peipei Wang, Peng Wang, Yuan Gan, G D Gu, Wei Zhang, Mingquan He, Liyuan Zhang

Journal of Physics: Condensed Matter · 31, 265702 (2019)

**AI thematic illustration**Concept artwork created for this paper.

Introduction

Transport and point-contact Andreev spectroscopy probe FeTe₀.₅₅Se₀.₄₅ near its coherence-length thickness. Films as thin as 5 nm retain a transition temperature close to the bulk value. Anisotropic critical fields and signatures of a BKT transition support quasi-two-dimensional superconductivity.

A closer reading

Transition temperatures, critical fields and gap spectroscopy address different aspects of how superconductivity survives thinning. The material's possible topological behaviour motivates the work, but these tests do not identify a Majorana bound state.