Hikami-Larkin-Nagaoka (HLN) Treatment of the Magneto-Conductivity of Bi2Te3 Topological Insulator
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We report the magneto-conductivity analysis at different temperatures under a magnetic field of up to 5 T of a well- characterized Bi2Te3 crystal. Details of crystal growth and various physical properties including high linear magneto-resistance are already reported by some of us. To elaborate upon the transport properties of Bi2Te3 crystal, the magneto-conductivity is fitted to the known Hikami-Larkin-Nagaoka (HLN) equation and it is found that the conduction mechanism is dominated by both surface-driven weak anti-localization (WAL) and the bulk weak localization (WL) states. The value of HLN equation coefficient (α) signifying the type of localization (WL, WAL or both WL and WAL) falls within the range of − 0.5 to − 1.5. In our case, the low-field (± 0.25 T) fitting of studied crystal exhibited a value of α close to − 0.86 for studied temperatures of up to 50 K, indicating both WAL and WL contributions. The phase coherence length (lφ) is found to decrease from 98.266 to 40.314 nm with increasing temperature. Summarily, the short letter reports the fact that bulk Bi2Te3 follows the HLN equation and quantitative analysis of the same facilitates to know the quality of studied crystal in terms of WAL to WL contributions and thus the surface to bulk conduction ratio.
KeywordsTopological insulator Magneto-resistance Conduction mechanism
The authors from the CSIR-NPL would like to thank their Director of NPL, India, for his keen interest in the present work. S. Patnaik thanks the DST-SERB project (EMR/2016/003998) for the low-temperature high-magnetic facility at the JNU, New Delhi, and Rabia Sultana and Ganesh Gurjar for the CSIR research fellowship. P. Neha thanks the UGC for the BSR fellowship. Rabia Sultana also thanks the AcSIR-NPL for the Ph.D. registration.