Logarithmic singularities and quantum oscillations in magnetically doped topological insulators

Abstract

We report magnetotransport measurements on magnetically doped $({\mathrm{Bi},\mathrm{Sb})}_{2}{\mathrm{Te}}_{3}$ films grown by molecular beam epitaxy. In Hall bar devices, we observe logarithmic dependence of transport coefficients in temperature and bias voltage which can be understood to arise from electron-electron interaction corrections to the conductivity and self-heating. Submicron scale devices exhibit intriguing quantum oscillations at high magnetic fields with dependence on bias voltage. The observed quantum oscillations can be attributed to bulk and surface transport.