Single-Electron Transistor Made of a 3D Topological Insulator Nanoplate

TL;DR

This paper reports the successful fabrication and characterization of a single-electron transistor using a 3D topological insulator nanoplates, demonstrating Coulomb blockade effects and paving the way for quantum topological devices.

Contribution

It introduces a reproducible nanofabrication method to create quantum confined systems in 3D topological insulators, enabling new research and applications.

Findings

Observation of Coulomb oscillations in the device

Demonstration of Coulomb diamond charge stability diagrams

Validation of tunneling junction functionality

Abstract

Quantum confined devices of three-dimensional topological insulators have been proposed to be promising and of great importance for studies of confined topological states and for applications in low energy-dissipative spintronics and quantum information processing. The absence of energy gap on the TI surface limits the experimental realization of a quantum confined system in three-dimensional topological insulators. This communication reports on the successful realization of single-electron transistor devices in Bi$_2$Te$_3$ nanoplates by state of the art nanofabrication techniques. Each device consists of a confined central island, two narrow constrictions that connect the central island to the source and drain, and surrounding gates. Low-temperature transport measurements demonstrate that the two narrow constrictions function as tunneling junctions and the device shows well-defined Coulomb current oscillations and Coulomb diamond shaped charge stability diagrams. This work provides a controllable and reproducible way to form quantum confined systems in three-dimensional topological insulators, which should greatly stimulate research towards confined topological states, low energy-dissipative devices and quantum information processing.