Superconductor-Insulator Transition in Ultra-Thin Sb2Te3 Nanoplates.

The conductivity of single-crystal nanoplates of the Sb₂Te₃ topological insulator has been investigated. A sharp drop in resistance occurs in ultrathin Sb₂Te₃ nanoplates at a temperature of about 4 K, which is a manifestation of superconductivity. The results show that the presence of an optimal degree of disorder is a necessary condition for the onset of superconductivity. A superconductor-insulator transition, tunable by a magnetic field, is observed in these nanoplates. The temperature dependence of the magnetoresistance in fields below the critical value (B < B_C) shows a successive transformation of a weak antilocalization anomaly into a superconducting transition. The value of the correlation length exponent ν = 0.75 ± 0.05 was obtained using the scaling theory. [ABSTRACT FROM AUTHOR]