News · 4 Oct 2026 · Quantum Zeitgeist
New design removes 98.4% of qubit leakage during measurement
A sourced note from the 5 October 2026 morning scan. The figure of record is the original report, not this page.
QuTech/TU Delft integrated a leakage reduction unit directly into transmon readout, using simultaneous drives on the qubit and its resonator (adapted from DDROP) to return leaked qubits to the computational subspace with no added measurement time. They report 98.4% leakage removal with 99.2% state-assignment fidelity, and suppressed logical error rates in memory and stability QEC experiments without post-selection; the paper is in PRX Quantum.
Why it matters
Leakage causes correlated errors that break standard error-correction assumptions; fixing it "for free" during measurement is a practical QEC win for superconducting machines.
Source: Quantum Zeitgeist — 4 Oct 2026