Overview
- Researchers led by Chen Xianhui and Wang Zhenyu report in a Nature Accelerated Article Preview that an STM tip carved from α‑Bi4Br4 produced converging, atomically resolved evidence for d‑wave altermagnetic order on the surface of KV2Se2O.
- The α‑Bi4Br4 tip is made by focused‑ion‑beam shaping and uses helical edge‑state tunneling so reversing the sample bias changes the tip’s spin sensitivity and reveals spin‑dependent contrast at the atomic scale.
- A wave of arXiv preprints published on Oct. 14 presents complementary advances, including a spectroscopic claim of number‑controllable Majorana zero modes in 1QL Bi2Te3/FeTe and new full‑spectrum and microscopic moiré/tunneling theories that revise flat‑band and pairing predictions.
- The Majorana and many theoretical results are currently preprints that need peer review and independent replication, while the topological‑tip application to KV2Se2O is now public through Nature’s accelerated preview and press reporting.
- Together these developments tighten the loop between instruments, experiments, and theory by giving a practical atomic‑scale probe for spin and topology and by supplying more realistic models to guide searches for correlated topological phases and quantum‑information platforms.