Engineering the in-plane anomalous Hall effect in Cd3As2 thin films

We predict two topological phase transitions for cadmium arsenide (Cd₃As₂) thin films under in-plane magnetic field, taking advantage of a four-band k model and effective g factors calculated from first principles. Film thickness, growth direction, and in-plane Zeeman coupling strength can all serve as control parameters to drive these phase transitions. For (001) oriented Cd₃As₂ thin films, a two dimensional Weyl semimetal phase protected by C₂ₙT symmetry can be realized using an in-plane magnetic field, which has recently been reported in our companion paper B. Guo, W. Miao, V. Huang, A. C. Lygo, X. Dai, and S. Stemmer, Phys. Rev. Lett. 131, 046601 (2023). We then put forth two pathways to achieve quantized in-plane anomalous Hall effects. By either introducing a trigonal warping term or altering the growth orientation, the emergent C₂ₙT symmetry can be broken. Consequently, in the clean limit and at low temperatures, quantized Hall plateaus induced by in-plane Zeeman fields become observable.