The quantum anomalous Hall effect (QAHE) was discovered
a decade
ago but is still not utilized beyond a handful of research groups,
due to numerous limitations such as extremely low temperature, electric-field-effect
gating requirement, small sample sizes, and environmental aging effect.
Here, we present a robust platform that provides effective solutions
to these problems. Specifically, on this platform, we observe QAH
signatures at record-high temperatures, with a Hall conductance of
1.00 e2/h at 2.0 K, 0.98 e2/h at 4.2 K, and 0.92 e2/h at 10 K, on centimeter-scale
substrates, without electric-field-effect gating. The key ingredient
is an active CrOx capping layer, which
substantially boosts the ferromagnetism while suppressing environmental
degradation. With this development, QAHE will now be accessible to
much broader applications than before.