# Four-qubit experiment extends logical coherence with fixed recovery cycles

_Published Monday, September 21, 2026 at 7:20 PM EDT · Science · Latest · Tier 2 — Notable_

Researchers at the Chinese Academy of Sciences demonstrated a four-qubit control method that extended logical coherence from approximately T1/4 nanoseconds to beyond T1 nanoseconds. The laboratory system compiles error recovery into repeating, open-loop waveforms, avoiding the syndrome measurements and real-time feedback normally used to diagnose and correct errors.

Frequency-selective drives apply local recovery rules inside a ring of superconducting transmon qubits, slowing logical decay under random Pauli-X disturbances. Spectral crowding can cause leakage, however, and the four-qubit result does not establish that the method will scale to the hundreds or thousands of stable qubits needed for fault-tolerant computation.

## Sources

- [quantumzeitgeist.com](https://quantumzeitgeist.com/qubit-decay-correction-cycles-four-bit-system/)

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Canonical: https://techandbusiness.org/newswire/u-KBTOfxlGuqNU8us7XjWc
Published: 2026-09-21T23:20:54.559Z
Story chronology: 2026-09-21T20:29:00.000Z
Retrieved: 2026-09-22T01:20:22.156Z
Publisher: Tech & Business (techandbusiness.org)