Theoretical modeling of magnetic phase evolution in bulk _n[Bi₂Te₃] x MnBi₂Te₄

The concept of electronic topology and the associated exotic states in quantum materials (QMs), such as the family of MnBi₂Te₄ (MBT), brings an excellent opportunity for developing next-generation nanodevices, especially those requiring high quantum mechanical coherence properties. MBT is an intrinsic antiferromagnetic topological insulator and displays Quantum Anomalous Hall Effect. This form of MBT requires a large magnetic field to present ferromagnetism; however, it has been discovered that this can be remedied by adding (n)Bi₂Te₃ quintuple layers to the system. A new experiment has also found phase transitions from antiferromagnetic states to ferromagnetic to paramagnetic, with each transition related to the bulk thickness of Bi₂Te₃. In this work, we use density functional theory (DFT) to observe how differences in energies and band structure reveal antiferromagnetic to ferromagnetic to nonmagnetic phase transitions of _n[Bi₂Te₃] x MnBi₂Te₄ (nMBT) derivative compounds. In addition, we plan to present differences between slab surface state structures and bulk structures and each form’s resulting impact on the nMBT derivatives’ electronic and magnetic properties.