Automated Superconducting Qubit Characterisation Platform Based on a Modified 3D Printer

TL;DR

This paper presents an automated platform using a modified 3D printer with microcontrollers for rapid, cost-effective superconducting qubit junction characterization, significantly reducing measurement time and enabling unsupervised operation.

Contribution

It introduces a novel, low-cost automated measurement system for superconducting qubits based on a modified 3D printer, improving speed and reducing manual effort.

Findings

Measurement time reduced by 28-51%

System costs approximately 800 SGD

Unsupervised operation achieved

Abstract

Josephson Junctions are important components in superconducting qubits. It introduces anharmonicity to the energy level spacings of the qubit which allow us to identify two unique quantum energy states for computing. It is difficult to fabricate multiple junctions within the same desired parameter range. Characterisation of the junctions is, therefore, a necessary step after fabrication. In particular, the critical current of the junctions is determined by measuring their normal state resistance. This is done via two-point or four-point resistance measurement at a manual probe station which is a time-consuming process, especially for wafer-scale fabrication. This bottleneck can be circumvented by automation with object detection. The base of the automated probe station is a 3D printer modified with multiple Arduino Uno microcontrollers and motorised linear stages. The automation process is achieved via auto-alignment of the probes and an automatic measurement procedure. As a result, the fully automated process will take about 27-29 seconds to measure the resistance of one junction which saves 28-51% of the time compared to the manual probe station and can be unsupervised. Due to the reuse of a commercial 3D printer, the cost of this system is 800 SGD which is much less than comparable commercial solutions.