Effects of Magnetic Doping on Weak Antilocalization in Narrow Bi2Se3 Nanoribbons

We report low-temperature, magnetotransport measurements of ferrocene-doped Bi2Se3 nanoribbons grown by vapor liquid solid method. The Kondo effect, a saturating resistance upturn at low temperatures, is observed in these ribbons to indicate presence of localized impurity spins. Magnetoconductances of the ferrocene-doped ribbons display both weak localization and weak antilocalization, which is in contrast with those of undoped ribbons that show only weak antilocalization. We show that the observed magnetoconductances are governed by a one-dimensional localization theory that includes spin orbit coupling and magnetic impurity scattering, yielding various scattering and dephasing lengths for Bi2Se3. The power law decay of the dephasing length on temperature also reflects one-dimensional localization regime in these narrow Bi2Se3 nanoribbons. The emergence of weak localization in ferrocene-doped Bi2Se3 nanoribbons presents ferrocene as an effective magnetic dopant source.