The University of Surrey's Quantum Sciences Group has introduced a conceptual design for a novel qubit that may significantly enhance the stability of quantum computing systems. The proposed Superfluid Helium Oscillator Quantum (SHOQ) device leverages charge-neutral superfluid helium-3, a form of liquid helium that flows without friction, to create a qubit less susceptible to electromagnetic interference. This design marks the first reported proposal for a qubit based on a superfluid.
Current quantum computers often rely on superconducting circuits, which are sensitive to electromagnetic noise and stray electrical charges. These disturbances can disrupt the delicate quantum information held within a qubit, leading to errors and hindering the scalability of quantum systems. The research team's calculations, published in npj Quantum Information, indicate that the SHOQ device could achieve error rates 100 times lower than those of conventional superconducting qubits.
Dr. Priya Sharma, a Daphne Jackson Fellow in Hybrid Quantum Systems at the University of Surrey's School of Mathematics and Physics and the lead author of the study, noted that while the individual components of this idea have been explored before, her team is the first to integrate them into a microfluidic device and define the specific details for its function as a qubit. The charge-neutral nature of superfluid helium is expected to provide inherent protection against certain types of electromagnetic noise.
The development of qubits with lower error rates is a critical step toward building fault-tolerant quantum computers. Quantum error correction typically requires a large number of physical qubits to encode a logical qubit, and a lower physical error rate is essential for this process to be effective. The ability to reduce errors at the hardware level could simplify the demands on error correction mechanisms.
The University of Surrey team is now working towards building a prototype to experimentally validate these theoretical predictions. This effort is supported by an IAA Commercialisation Fellowship awarded to Dr. Sharma. The conditions necessary for operating the SHOQ device, specifically extremely low temperatures, have already been achieved in existing superfluid helium-3 research. Dr. Eran Ginossar, an Associate Professor at the University of Surrey and co-author of the study, suggested that combining different quantum technologies, such as this superfluid-based qubit with existing superconducting systems, could allow researchers to capitalize on the strengths of each approach.