Nat. Commun. New hardware will scale up industrial applications of quantum computers

A team led by the University of Minnesota-Twin Cities has developed a new superconducting diode - a key component in electronic devices that could help scale up the industrial use of quantum computers and improve the performance of artificial intelligence systems. Compared to other superconducting diodes, the researchers' device is more energy efficient, can process multiple electrical signals simultaneously and contains a series of "gates" that control the flow of energy: functions that have never before been integrated into a superconducting diode.

The paper was published in Nature Communications on May 29.

The diode allows current to flow in one direction in a circuit, but not the other. It is essentially half the size of a transistor and the main element of a computer chip. Diodes are usually made from semiconductors, but researchers are interested in making them from superconductors, which have the ability to transmit energy without losing any energy in the process.

We want to make computers more powerful, but our current materials and fabrication methods are quickly running into some hard limits," said Vlad Pribiag, senior author of the paper and an associate professor in the School of Physics and Astronomy at the University of Minnesota. So we need new ways to develop computers, and one of the biggest challenges to improving computing power right now is that they dissipate too much energy. What we are considering is that superconductivity may help solve this problem."

The University of Minnesota-Twin Cities team has developed a more energy-efficient, tunable superconducting diode that could help scale up quantum computers for industry and improve artificial intelligence systems.

Device structure

Josephson diode effect.

Researchers at the University of Minnesota created the device using three Josephson junctions, which are made by sandwiching pieces of non-superconducting material between superconductors. In this case, the researchers connected the superconductors with a semiconductor layer. The unique design of the device allows the researchers to use voltage to control this device.

Their device also has the ability to handle multiple signal inputs, whereas a typical diode can only handle one input and one output. This feature may have applications in neuromorphic computing - a circuit engineering method that mimics the way neurons operate in the brain, which in turn could improve the performance of artificial intelligence systems.

Mohit Gupta, first author of the paper and a doctoral student at the University of Minnesota's School of Physics and Astronomy, explains, "We have built a device with near the highest energy efficiency ever; and, for the first time, we have shown that this can be tuned by adding 'gates' and applying electric fields to We also showed for the first time that this effect can be adjusted by adding 'gates' and applying electric fields. Other researchers have built superconducting devices before, but the materials they used were very difficult to manufacture. Our design uses materials that are more friendly to industry and offers new capabilities."

The method used by the researchers could in principle be used for any type of superconductor, making it more versatile and easier to use than other techniques in the field. Because of these qualities, their devices are more compatible with industry applications and could help scale up the development of quantum computers for a wider range of applications.

"Right now, all quantum computing machines are very basic relative to the needs of real-world applications." Pribiag said, "Scaling up is necessary to have a computer that is powerful enough to solve useful and complex problems. A lot of people are working on algorithms and use cases for computers or artificial intelligence machines that have the potential to surpass classical computers. Here, we are developing hardware that will enable quantum computers to implement these algorithms, and these ideas will eventually make their way into industry and be integrated into practical machines."

Reference links:

[1] https://www.nature.com/articles/s41467-023-38856-0

[2] https://phys.org/news/2023-06-superconducting-diode-quantum-artificial-intelligence.html