Heat Destroys Quantum Properties in Superconductor Materials
Researchers discovered that heating iron chalcogenide superconductors causes their prized quantum properties to vanish, even though the material's fundamental structure remains unchanged. The finding threatens the viability of these materials for next-generation quantum devices and suggests engineers must rethink how to engineer stable topological materials for real-world applications.
Originaltitel: Fragility of Topology under Electronic Correlations in Iron Chalcogenides
The interplay between electronic correlations and topology is a central topic in the study of quantum materials. In this work, we investigate the impact of the orbital-selective Mott phase (OSMP) on the topological properties of FeTe1-xSex (FTS), an iron chalcogenide superconductor known to host both non-trivial Z2 topology and strong electronic correlations. Using angle-resolved photoemission spectroscopy, we track the evolution of topological surface states across various doping levels and temperatures. We identify a topological phase transition between trivial and non-trivial topology as a function of selenium content, with critical behavior observed between x = 0.04 and x = 0.09. Additionally, we find that at elevated temperatures, the coherence of the topological surface state deteriorates due to the emergence of OSMP, despite the topological invariant remaining intact. Our results demonstrate that the non-trivial topology in iron chalcogenide is fragile under strong electronic correlations.