Electrical control of uniformity in quantum dot devices

TL;DR

This paper introduces an electrical tuning method to improve uniformity in quantum dot devices, enhancing their suitability for scalable quantum computing by stabilizing and homogenizing device characteristics.

Contribution

The authors develop a technique to electrically achieve high uniformity in quantum dot potential landscapes, significantly reducing variability in device parameters.

Findings

Pinch-off voltages can be tuned over hundreds of millivolts and remain stable for hours.

Homogenization of pinch-off voltages reduces variability by an order of magnitude.

The method offers a new tool for scalable quantum dot device fabrication.

Abstract

Highly uniform quantum systems are essential for the practical implementation of scalable quantum processors. While quantum dot spin qubits based on semiconductor technology are a promising platform for large-scale quantum computing, their small size makes them particularly sensitive to their local environment. Here, we present a method to electrically obtain a high degree of uniformity in the intrinsic potential landscape using hysteretic shifts of the gate voltage characteristics. We demonstrate the tuning of pinch-off voltages in quantum dot devices over hundreds of millivolts that then remain stable at least for hours. Applying our method, we homogenize the pinch-off voltages of the plunger gates in a linear array for four quantum dots reducing the spread in pinch-off voltage by one order of magnitude. This work provides a new tool for the tuning of quantum dot devices and offers new perspectives for the implementation of scalable spin qubit arrays.