Observation of Rashba Effect and Nonreciprocal Transport in Bi2Te3

Abstract

Topological insulators (TIs) represent a unique state of matter that has attracted significant interest in condensed matter physics due to their surface conduction states with high spin polarization. Despite extensive studies on the properties of TIs, there has been limited exploration of the Rashba parameter and large-scale film growth. In this work, we investigate the Rashba effect in molecular-beam-epitaxy(MBE)-grown Bi2Te3 channels by measuring anisotropic magnetoresistance (AMR). The extracted Rashba parameter is as large as 16.3 eV<middle dot>& Aring;, significantly exceeding values reported in previous studies. This strong Rashba field is attributed to the minimization of imperfections and crystal defects during film fabrication. Furthermore, nonreciprocal charge transport induced by the Rashba-like effective field is clearly observed up to room temperature through harmonic resistance measurements. The temperature dependence of the nonreciprocal coefficient exhibits a non-monotonic behavior, which is believed to arise from the temperature dependence of the Fermi level position.