• Lippertz, Gertjan
• Uday, Anjana
• Luysberg, Martina
• Bliesener, Andrea
• Ando, Yoichi
• Taskin, Alexey A.
• Wei, Xiankui
• Bai, Mengmeng
• Mayer, Joachim
• Feng, Junya

Abstract

<jats:title>Abstract</jats:title><jats:p>When a topological insulator is made into a nanowire, the interplay between topology and size quantization gives rise to peculiar one-dimensional states whose energy dispersion can be manipulated by external fields. In the presence of proximity-induced superconductivity, these 1D states offer a tunable platform for Majorana zero modes. While the existence of such peculiar 1D states has been experimentally confirmed, the realization of robust proximity-induced superconductivity in topological-insulator nanowires remains a challenge. Here, we report the realization of superconducting topological-insulator nanowires based on (Bi<jats:sub>1−<jats:italic>x</jats:italic></jats:sub>Sb<jats:sub><jats:italic>x</jats:italic></jats:sub>)<jats:sub>2</jats:sub>Te<jats:sub>3</jats:sub> (BST) thin films. When two rectangular pads of palladium are deposited on a BST thin film with a separation of 100–200 nm, the BST beneath the pads is converted into a superconductor, leaving a nanowire of BST in-between. We found that the interface is epitaxial and has a high electronic transparency, leading to a robust superconductivity induced in the BST nanowire. Due to its suitable geometry for gate-tuning, this platform is promising for future studies of Majorana zero modes.</jats:p>

Topics

• impedance spectroscopy
• dispersion
• thin film
• one-dimensional
• superconductivity
• superconductivity
• palladium