Fig. 1: Atomic structure and potential energy map of three septuple layers (SL) MnBi2Te4 (MBT).

a Crystal structure of 3-SL MBT, with Mn, Bi and Te atoms denoted as purple, blue and gray balls, respectively. Lateral shift of the bottom SLs relative to the top SL is denoted by the vector d. b Stacking energy of 3-SL MBT as a function of lateral shift vector d, compared to the ABC-stacking MBT.