We investigate magnetism and band structure engineering in Moir\'e superlattice of blue phosphorus (β-P) and grey arsenene (β-As) bilayers, using \textit{ab initio} calculations. The electronic states near the valence and conduction band edges have significant pz character in both the bilayers. Thus, twisting the layers significantly reduce the interlayer orbital overlap, leading to a decrease in the binding energy (up to ∼33%) and an increase in interlayer distance (up to ∼10%), compared to the most stable AA-stacking. This interlayer decoupling also results in a notable increase (up to ∼25-50\%) of the bandgap of twisted bilayers, with the valance band edge becoming relatively flat with van-Hove singularities in the density of states. Thus, hole doping induces a Stoner instability, leading to ferromagnetic ground state, which is more robust in Moir\'e superlattices, than that of AA-stacked β-P and β-As.
@article{arxiv.1905.05951,
title = {Interlayer decoupling in twisted bilayers of $\beta$-phosphorus and arsenic: a computational study},
author = {Shantanu Agnihotri and Maneesh Kumar and Yogesh Singh Chauhan and Amit Agarwal and Somnath Bhowmick},
journal= {arXiv preprint arXiv:1905.05951},
year = {2019}
}