Site-Controlled Ge Hut Wire-Based Multiple Quantum Dots with Integrated Charge Sensing Capability

Abstract

Scalability represents a fundamental challenge in advancing semiconductor-based quantum computing architectures. Germanium nanowires (NWs) have emerged as a highly promising platform due to their demonstrated high-quality in-plane NW networks. In this study, we demonstrate the fabrication of two distinct sets of multiple quantum dots (QDs) on closely spaced parallel Ge hut wires. Charge sensing is achieved through capacitive coupling between the two sets of QDs. Furthermore, the tunability of both sets of QDs enables mutual detection between dot pairs across arrays.Through systematic gate voltage adjustments, we successfully transition the system configuration from a single quantum dot (SQD) to triple quantum dot (TQD) regimes.We identify edge state impurities in one set of QDs, which may introduce crosstalk effects and potentially hinder qubit detection and manipulation. Through comprehensive analysis and numerical simulations of these edge states, we hope to develop approaches to avoid the formation of such edge state impurities in the future.