MilestoneHardwareClaimed

Alice & Bob says its cat qubits resisted bit-flip errors for about an hour

Sep 25, 2025

In September 2025, the French startup Alice & Bob reported early results in which a cat qubit (a superconducting qubit that stores information in a resonator) went an average of 44 minutes between bit-flip errors, up from about 7 minutes in 2024. Qubits on its 12-qubit Helium 2 chip went longer.

Why it matters

Cat qubits aim to make one of the two kinds of error so rare that error correction only has to fight the other, which would cut the hardware a useful machine needs. Phase flips still occur.

Alice & Bob

See it on the timeline

Alice & Bob estimates RSA-2048 could be broken with about 23,000 cat qubits (Oct 29, 2026)
Researchers propose encoding protected qubits in cat states (Sep 14, 1998)

Sources (3)

Alice & Bob Just Out of the Lab: A Cat Qubit That Jumps Every Hour
Primary source

“We count a total of 41 bit-flips over 61 hours, which implies an average bit-flip time of 44 minutes.”
The Quantum Insider Alice & Bob's Preliminary Results Vastly Surpass Previous Bit-Flip Time Record
Independent coverageSep 25, 2025

“Alice & Bob reported that their cat qubits maintained resistance to bit-flip errors for more than one hour, surpassing the previous record of 430 seconds set in 2024.”
Quantum Computing Report Alice & Bob Demonstrates Multi-Hour Physical Bit-Flip Suppression on Single-Cat and Helium 2 Processors
Independent coverageNov 2, 2026

“measuring macroscopic bit-flip lifetimes exceeding one hour on its bosonic cat-qubit hardware”

Added Nov 2, 2026. Spotted an error? Tell us and we will review it.

Alice & Bob says its cat qubits resisted bit-flip errors for about an hour

Why it matters

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