Brookhaven Lab: A Silicon-Compatible Path Toward Scalable Quantum Systems

Key Takeaways

• Transition metal silicide SQUIDs fabricated on silicon substrates using CMOS‑compatible processes
• Constriction junctions replace traditional Josephson junctions, offering mass‑production potential
• Devices operated at 350 mK, showing nonlinearity essential for high‑performance qubits
• Collaboration between Brookhaven, NY Creates, and C2QA accelerates silicon‑based quantum scaling

Pulse Analysis

Silicon has been the workhorse of the electronics industry for more than seven decades, underpinning everything from smartphones to data centers. As quantum computing matures, the industry faces a similar scaling challenge: moving from laboratory‑scale qubit demonstrations to mass‑manufacturable devices. Researchers have explored a variety of materials—sapphire, niobium, and exotic compounds—to achieve the necessary superconducting properties, but each brings its own fabrication hurdles. The recent Brookhaven effort demonstrates that transition‑metal silicides, already familiar to semiconductor fabs, can serve as a viable superconducting platform, bridging the gap between quantum physics and high‑volume manufacturing.

The Brookhaven team, in partnership with NY Creates and the DOE‑backed Co‑design Center for Quantum Advantage (C2QA), employed standard lithography and etching tools to create SQUIDs with constriction junctions. Unlike traditional Josephson junctions that rely on an insulating barrier, these constrictions consist of a narrow superconducting wire linking two silicide layers, simplifying the stack and reducing process steps. Measurements at 350 mK revealed the expected nonlinear inductance, confirming that the devices meet the fundamental criteria for transmon qubits. By demonstrating this architecture on a silicon wafer, the researchers prove that quantum devices can be integrated into existing CMOS lines, potentially allowing fab‑scale production without the need for exotic materials or bespoke equipment.

The implications for the quantum ecosystem are significant. A silicon‑compatible fabrication route could lower capital expenditures for quantum chip manufacturers, enable tighter supply chains, and accelerate the transition from prototype to commercial quantum processors. Moreover, the collaborative model—uniting national labs, industry partners, and academic researchers—exemplifies the multidisciplinary approach required to solve the scaling problem. As the DOE continues to fund quantum initiatives, breakthroughs like this position the United States to lead the next wave of quantum hardware innovation, translating scientific advances into market‑ready technologies.