Bottom-up Synthesis of Magnetic Topological Insulator

The infusion of magnetic dopants into a topological insulator can induce magnetic order within the substance, disrupting the time-reversal symmetry inherent to its surface electronic states. The absence of this symmetry allows topological insulators to display a variety of unique quantum phenomena that are theoretically interesting and underexplored, such as the quantum anomalous Hall effect, chiral Majorana modes, and topological magnetoelectric effects. In this study, we employed atmospheric pressure chemical vapor deposition (CVD) to fabricate Mn-doped Bi₂Te₃, a magnetic topological insulator, from the bottom up. To characterize our samples, we utilized optical microscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy. By systematically modifying each CVD growth parameter individually, we were able to ascertain the optimal values and permissible ranges of several parameters. This research illustrates a straightforward, scalable, and cost-effective method for synthesizing Mn-doped Bi₂Te₃ crystals using CVD that can provide precise control over the stoichiometry of the grown material and facilitates the fabrication of high-quality, few-layer crystals. These attributes position CVD as a valuable and promising technique for future investigations into magnetic topological insulators.