Researchers at the University of Hong Kong (HKU) have unveiled a significant advance in cryogenic electronics that could help overcome key challenges in quantum computing and support future deep space missions. The team, from HKU’s Department of Electrical and Computer Engineering and the Centre for Advanced Semiconductors and Integrated Circuits (CASIC), developed a programmable neuromorphic hardware platform capable of operating at temperatures near absolute zero.
The research was led by Professor Yuhao Zhang and PhD student Xin Yang. Their work introduces a new method for generating and controlling negative differential resistance (NDR) in industry standard Silicon Carbide (SiC) MOSFETs. Using this approach, the researchers demonstrated for the first time that a single transistor can reproduce the energy efficient “spiking” activity of biological neurons at temperatures as low as 10mK.
Brain-Inspired Hardware for Quantum Computing
Quantum computers depend on sophisticated control electronics to manage qubits, which are highly sensitive and must be kept at millikelvin temperatures. Existing silicon based control systems consume considerable power and produce unwanted heat, making it necessary to position them away from the qubits themselves. That distance creates extensive wiring requirements that can hinder performance and make large scale quantum computers more difficult to build.
“Our work introduces a hardware platform that can be integrated alongside quantum processors,” said Professor Zhang. “By using the unique carrier dynamics in silicon carbide, we can create circuits that are thousands of times more energy-efficient than conventional electronics, significantly reducing the thermal load on cryogenic systems.”
Silicon Carbide Reveals Unique Cryogenic Behavior
The team found that SiC MOSFETs display a strong “S-shape” NDR effect when cooled below 2K. This behavior is driven by electron-donor impact ionization (EDII). Unlike other technologies that depend on heat generated within a device, the newly observed mechanism arises directly from the material’s atomic properties. As a result, it remains highly stable and can be reproduced consistently across different manufacturing batches.
“This is a robust and scalable approach,” said Mr. Yang. “Because SiC is already used globally in electric vehicles and power grids, we can leverage existing industrial foundries to manufacture these cryogenic chips on 300-mm wafers.”
From Artificial Neurons to Deep Space Missions
The study also demonstrated that these artificial neurons can be linked together, or “cascaded,” into larger networks. This capability could enable advanced local data processing at cryogenic temperatures and improve important quantum computing functions such as quantum error correction and real time quantum control.
The potential applications extend well beyond quantum computing. Because the circuits are designed to operate reliably in extremely cold environments, they could also be valuable for deep space exploration. Future systems may be able to function in the harsh conditions found on the Moon’s surface or in the distant regions of our solar system.
The findings were published in Nature Communications in a paper titled “Cryogenic neuromorphic circuits using gate-controlled negative differential resistance in silicon carbide.”
