Supercomputers are playing an increasingly important role for our society by performing calculations with a variety of implications ranging from weather forecasting to genetic material sequencing to testing of drugs for new diseases. Enhancing the performance of modern supercomputers, whilst minimizing their energy losses, represent two contrasting but major needs that the information technology industry will have to address in the future.
As a participant of the international research network SuperGate (Gate Tuneable Superconducting Quantum Electronics), researchers from Chalmers are now taking part in an EU-funded project to create a new basis for the super-computers of tomorrow: to develop a bridging technology that combines superconductor technology with semiconductor technology, using an approach that was considered physically impossible until just a few years ago. The two technology systems have up till then been considered incompatible in the sense that semiconductors are controlled by voltage and operate at room temperature, while superconductors, on the other hand, are based on current and operate at temperatures of around minus 270 degree Celsius, near absolute zero. Combining the more powerful and more energy-efficient superconductor technology with existing semiconductor technology is of great interest in high-performance computer development.
– This project will shed some light on a physical effect that we do not fully understand, and, at the same, it provides a clear pathway to utilization, says Simone Gasparinetti, project leader of the research team from the department of Microtechnology and Nanoscience at Chalmers University of Technology.
A path-breaking discovery
The SuperGate research project is coordinated by the University of Konstanz and funded with around 3 million euros through an FET Open Grant (FET: Future and Emerging Technologies) of the European Union. The idea behind the project stems from a path-breaking discovery made by physicists at the Consiglio Nazionale delle Ricerche (CNR) in Pisa (Italy). They managed to demonstrate that superconductivity in a weak link can be controlled by applying voltages to electrostatic gates, in a similar way as semiconducting transistors are controlled by the field effect. This discovery has the potential to revolutionize the world of supercomputing, leading to a technology that would combine the advantages offered by semiconductors and superconductors. A discovery that didn’t go unnoticed by the researchers at the department of Microtechnology and Nanoscience at Chalmers.
– Back a few years ago, after seeing the first results of Pisa group, I got curious about them and started to run some experiments in our lab. However, it was a sideline project, run on very limited resources, and progress has been slow. With SuperGate, we finally have a chance to give it a real shot, says Simone.
Paving the way for supercomputers of tomorrow
However, despite its potential for applications, the underlying physical mechanism behind gated superconductivity is still unclear. In addition, the control has been demonstrated only at low frequencies (dc and audio band), while the prospected applications require switching at much higher frequencies (GHz and above). The main task for the Chalmers research team is to investigate the origin of the effect and test the response at high frequencies. In order to optimize speed and performance the Chalmers team will try out different materials and geometries and finally develop a range of logic circuits and combine them with conventional semiconductor technology.
– Our task will be to investigate the gated superconducting weak links at high frequencies. Thanks to our background in rf and microwave measurements of superconducting circuits, our team are uniquely suited for this challenge, says Simone.
The SuperGate research network consists of a consortium of four universities, one research institute and a world-leading company in superconducting electronics – representing a diversity in backgrounds, bringing together complementary knowledge. And if successful, the research project might contribute to the development of both future supercomputers as well as quantum computers.
– If these devices can be operated at high frequencies, I see applications in the context of quantum information processing that go beyond the scope of the project, and my team will be in an ideal position to explore them. Even if we are looking at a “classical” supercomputer, the materials that we will investigate are compatible with the technology that WACQT is using to build a quantum computer. Many of the things we will learn can be of interest for our quantum technology division and for the full MC2 department, which has a long and successful tradition in material science, concludes Simone.
Key facts about SuperGate research project
The international research network “Gate Tuneable Superconducting Quantum Electronics” (SuperGate) is funded through an FET Open Grant of the European Union.
Funding sum: 3 million euros
Funding period: March 2021 to August 2024
Project partners: University of Konstanz, CNR laboratories at Pisa and Salerno, Budapest University of Technology and Economics, Delft University of Technology, Chalmers University of Technology at Gothenburg, SeeQC-EU (Italy)
The Wallenberg Centre for Quantum Technology, WACQT, is a 12 year research center that aims to take Sweden to the forefront of quantum technology. The main project is to develop an advanced quantum computer. WACQT is coordinated from Chalmers University of Technology, and has activities also at the Royal Institute of Technology, Lund University, Stockholm University, Linköping University and Göteborg University.