Environmental Doping-Induced Degradation of the Quantum Anomalous Hall Insulators

Han Tay, Yi Fan Zhao, Ling Jie Zhou, Ruoxi Zhang, Zi Jie Yan, Deyi Zhuo, Moses H.W. Chan, Cui Zu Chang

Research output: Contribution to journalArticlepeer-review

2 Scopus citations


The quantum anomalous Hall (QAH) insulator carries dissipation-free chiral edge current and thus provides a unique opportunity to develop energy-efficient transformative information technology. Despite promising advances, the QAH insulator has thus far eluded any practical applications. In addition to its low working temperature, the QAH state in magnetically doped topological insulators usually deteriorates with time in ambient conditions. In this work, we store three QAH devices with similar initial properties in different environments. The QAH device without a protection layer in air shows clear degradation and becomes hole-doped. The QAH device kept in an argon glovebox without a protection layer shows no measurable degradation after 560 h, and the device protected by a 3 nm AlOx protection layer in air shows minimal degradation with stable QAH properties. Our work shows a route to preserve the dissipation-free chiral edge state in QAH devices for potential applications in quantum information technology.

Original languageEnglish (US)
Pages (from-to)1093-1099
Number of pages7
JournalNano letters
Issue number3
StatePublished - Feb 8 2023

All Science Journal Classification (ASJC) codes

  • Bioengineering
  • General Chemistry
  • General Materials Science
  • Condensed Matter Physics
  • Mechanical Engineering

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