Further Developments and Applications

Jia Du

The CSIRO Applied Superconductivity Group has a long-term effort in research and development of superconducting electronic devices and systems for various practical applications. In this paper, I will mainly describe our recent research progress in developing novel HTS Josephson devices for high frequency applications. Specifically, we have recently developed a novel HTS Josephson heterodyne gigahertz (GHz) microwave oscillator and on-chip down-converter (mixer). For even higher frequency application, we developed a HTS Josephson junction terahertz (THz) detector and applied it successfully to THz imaging. I will highlight some of the recent results and describe the on-going effort of developing an array of such detectors and associated electronics as well as system integration.

Jake Zappin, Trevor Stalnaker, Oscar Chaparro +1 more

Recent advances in quantum computing have sparked excitement that this new computing paradigm could solve previously intractable problems. However, due to the faulty nature of current quantum hardware and quantum-intrinsic noise, the full potential of quantum computing is still years away. Hybrid quantum-classical computing has emerged as a possible compromise that achieves the best of both worlds. In this paper, we look at hybrid quantum-classical computing from a software engineering perspective and present the first empirical study focused on characterizing and evaluating recurrent issues faced by developers of hybrid quantum-classical applications. The study comprised a thorough analysis of 531 real-world issues faced by developers - including software faults, hardware failures, quantum library errors, and developer mistakes - documented in discussion threads from forums dedicated to quantum computing. By qualitatively analyzing such forum threads, we derive a comprehensive taxonomy of recurring issues in hybrid quantum-classical applications that can be used by both application and platform developers to improve the reliability of hybrid applications. The study considered how these recurring issues manifest and their causes, determining that hybrid applications are crash-dominant (74% of studied issues) and that errors were predominantly introduced by application developers (70% of issues). We conclude by identifying recurring obstacles for developers of hybrid applications and actionable recommendations to overcome them.

Mark S. Swanson

Karl Blum

Jia Du

The CSIRO Applied Superconductivity Group has a long-term effort in research and development of superconducting electronic devices and systems for various practical applications. In this talk, I will give an overview of CSIRO research activities in developing high-Tcsuperconducting (HTS) Josephson junction devices for various applications. I will firstly describe the CSIRO-developed HTS step-edge Josephson junction technology and its basic application in Superconducting Quantum Interference Devices (SQUIDs). I will then describe in more detail our recent research progress on developing high-Tcsuperconducting (HTS) Josephson devices for microwave and terahertz (THz) applications.