At small magnetic field, 2L CrPS 4 can be in one of the two stateswith opposite magnetization in the top and bottom layerslabelled as A (left column) and B (right column). These states are energetically degenerate ( E A = E B ) in the absence of gate-induced electrons ( n e = 0) or when electrons equally occupy both layers ( D / ε 0 = 0). The degeneracy is broken at finite n e and perpendicular electric field D / ε 0 , in the presence of a perpendicular magnetic field. The state with lower energy is determined by the sign of the applied electric and magnetic fields, because the energy difference arises from the Zeeman energy of accumulated electrons thata low n e occupy states in one of the two layers (and are therefore spin-polarized with spin pointing in opposite directions; Fig. 1a ).
