Fermilab SQMS Center Identifies Microscopic Origins of Qubit Performance Variance Across Superconducting Transmons
AI-summarised brief · reviewed before publication
A multi‑institution study led by Fermilab’s SQMS Center, in partnership with Rigetti Computing, NIST, Ames Lab, Northwestern University, and the NPL, identified microscopic defects that cause performance variation in superconducting transmon qubits. The research, published in Applied Physics Reviews, correlated nanoscale fabrication features—such as surface oxide thickness, trench depth, and sidewall etch profiles—with energy‑relaxation times (T1). Using a double‑blind protocol on 22 devices, the team found that single‑nanometer shifts in these parameters can double T1 lifetimes, while larger surface defects showed no clear impact. Rigetti is applying these findings to refine lithography and passivation, aiming to improve yield uniformity in multi‑qubit processors.
💡 Why It Matters
- · By pinpointing the exact nanoscale defects that degrade qubit coherence, the study provides a practical roadmap for manufacturers to standardize qubit performance, a critical step toward scalable, fault‑tolerant quantum computers.