Gapless topological surface states are explained by stacking-fault disorder

Scientific Achievement: A gapless surface state with non-trivial topological properties is shown to result solely from stacking-fault disorder at the MnBi₂Te₄ (MBT) surface.

Significance and Impact: Our findings provide a new explanation to the long-standing puzzle of how to reconcile contradictory surface gap measurements in various MBT samples.

DOI: 10.1021/acs.jpclett.3c01939