Researchers at Brookhaven National Laboratory have made a significant breakthrough in quantum computing, developing a qubit architecture that is more amenable to mass production. This research could pave the way for the scalable manufacturing of quantum computer building blocks, bringing us closer to the realization of practical quantum computers.
Solving the manufacturing problem
The superconductor-insulator-superconductor (SIS) junction that’s the most widely used qubit architecture today is a hard thing to make in the large number needed for solving practical quantum computing problems.
At Brookhaven National Laboratory, meanwhile, researchers have been looking at an alternative design — a superconductor-constriction-superconductor (SCS) junction that is better suited for conventional semiconductor fabrication.
SCS stacks come flat so they are easier to fabricate; SCD is great as a small dish. On the other hand, this architectural change comes with its own set of problems because SCS junction is fundamentally more linear than SIS junction; a fundamental bad part if it exists to Superconducting qubits.
Narrowing the Bandwidth Bottleneck
Researchers Goldie (left) and Zwickl have determined that the SCS junction’s nonlinearity depends on the exact superconducting materials chosen and also how one designs, shapes, and sizes the junction.
In highlighting the particular tradeoffs between electrical resistance within the material and the junction’s nonlinearity, the researchers have delivered a road-map for materials scientists to create superconducting materials that are performant as qubits in 5-10 gigahertz frequency range.
This work has underlined the critical nature of interdisciplinary collaboration between quantum scientists and materials scientists as they strive to meet the demands for performing large-scale quantum-affinity computing.
Conclusion
Quantum computers are on the verge of an evolutionary phase in their architecture, and a solid milestone in this direction have been made by researchers at Brookhaven National Laboratory. The team has overcome key barriers presented by the current leading qubit design which if solved will allow quantum computing technologies to be more easily and confidently developed at scale. Rather, technologically advanced research— such as this effort with the Co-design Center for Quantum Advantage (C2QA)— represents a milestone of what can happen when different fields of science collaborate to push forth the realm of quantum computing.
