Quantum computers hold the promise of solving problems far beyond the capabilities of today’s supercomputers. At the heart of these systems are qubits—particularly, fluxonium qubits, which require superinductors to preserve delicate quantum states. But conventional superinductors, typically made from low-temperature superconductors like aluminium, only operate near absolute zero (–272°C). This demands complex cryogenic setups, limiting scalability and real-world deployment.
Now, researchers from the School of Physical and Mathematical Sciences (SPMS) at NTU Singapore, together with collaborators from IIT Hyderabad, CNRS Paris, and the University of Notre Dame, have demonstrated a new class of high-temperature-compatible (High-Tc) superinductors based on YBa₂Cu₃O₇ (YBCO)—a material that superconducts at much more practical temperatures.
Published in Nature Materials, the study offers a fundamentally new approach to designing superinductors. Led by Professor Ranjan Singh and PhD student Pang Teng Chen Ietro, the team harnessed the unique properties of high-Tc superconductors to overcome long-standing fabrication and thermal constraints.
“The requirement for extremely low temperatures has long constrained the scalability and accessibility of quantum computers. By pioneering a new class of high-temperature-compatible superinductors, our work challenges this paradigm,” said Professor Ranjan Singh from SPMS, NTU Singapore.
A Novel Route to Superinductance
Traditional superinductors rely on nanoscale Josephson junctions and highly ordered geometries to achieve high kinetic inductance—a measure of how effectively a material can oppose changes in current. These systems, while effective, are difficult to manufacture and require ultra-cold environments.
In contrast, the NTU-led team embraced the natural disorder in YBCO. By deliberately retaining and controlling micrometre-scale vortices—tiny regions where superconductivity is locally suppressed—they increased the material’s kinetic inductance to the levels required for superinductance.
This strategy of “defect engineering” represents a significant shift: rather than eliminating imperfections, the team exploited them. The result was an inductance exceeding the resistance quantum RQ=6.47 kW, the benchmark for superinductors.
“By harnessing the exotic properties of high-temperature superconductors, we’ve demonstrated a fundamentally new route to achieving superinductance—one that sidesteps the extreme cooling and complex nanofabrication required by traditional approaches,” explained PhD candidate Pang Teng Chen Ietro from SPMS, NTU Singapore.
Toward Real-World Quantum Devices
By enabling superinductors to function at higher temperatures and with more accessible fabrication methods, the research paves the way for scalable, cost-effective quantum processors. In addition to fluxonium-based quantum circuits, such superinductors could enhance the performance of terahertz detectors, radio telescopes, and space-based sensing systems.
What’s Next
The team plans to further refine the performance and stability of their YBCO-based superinductors and explore integration into quantum hardware and high-frequency sensing platforms.
“By pushing the boundaries of high-temperature superinductors, we are paving the way for more efficient quantum technologies, advanced sensing systems, and next-generation superconducting electronics,” added Professor Ranjan Singh.
Read the full paper in Nature Materials: YBa₂Cu₃O₇ as a high-temperature superinductor