Superconductivity and Superconductor-Insulator Transition in Single Crystal Sb2Te3 Nanoflakes

TL;DR

This study investigates the transport properties of ultrathin Sb2Te3 nanoflakes, revealing superconductivity and a superconductor-insulator transition influenced by disorder and magnetic fields in a topological insulator system.

Contribution

It demonstrates the emergence of superconductivity and a superconductor-insulator transition in Sb2Te3 nanoflakes, highlighting the role of disorder and magnetic field effects in topological insulator nanostructures.

Findings

Superconducting transition observed near 3K in ultrathin Sb2Te3 nanoflakes.

Magnetic field induces a superconductor-insulator transition in the nanoflakes.

Optimal disorder level is necessary for superconductivity to emerge.

Abstract

We report on transport properties of the topological insulator single crystal $Sb2Te3$ nanoflakes with thickness about from 7 to 50nm. A steep drop of resistance is appeared near $3K$ in the ultrathin $Sb2Te3$ nanoflakes, manifesting a superconducting transition.The magnetic field induced superconductor insulator transition of disordered 2D superconductor system is observed in the nanoflakes.The results show that the existence of certain optimum degree of disorder is a necessary condition for emergence of superconductivity.Temperature dependence of magneto-resistance shows a consecutive transformation of weak antilocalization cusp into the superconducting transition at low field when $B < BC$.