Topological insulating state in bismuth doped with antimony and arsenic: infrared and magneto-optical studies

Bismuth and its alloys with antimony have attracted attention in recent years due to the possibility of having a topological insulating state. In this study we have used infrared and magneto-optical spectroscopies to probe the electrodynamic response of bismuth doped with of antimony and arsenic. The spectra will be presented for temperatures down to 5 K, and in magnetic fields as high as 18 Tesla. The results have revealed a strong magneto-optical activity, especially around the plasma minimum in reflectance. These findings will be compared and contrasted with magneto-optical results from other 3D topological insulators.