# Alice & Bob and ENS Lyon stabilize cat qubits with DC voltage bias

Canonical page: https://technooptimist.io/stories/alice-and-bob-and-ens-lyon-stabilize-cat-qubits-with-dc-voltage-bias-f130d536
Date: 1 Oct 2026
About: [Alice & Bob](https://technooptimist.io/companies/alice-and-bob.md) · [Cat-qubit roadmap](https://technooptimist.io/quantum/cat-qubits.md)
Original source: https://quantumcomputingreport.com/alice-bob-and-ens-lyon-demonstrate-dc-biased-squid-architecture-for-multi-photon-cat-qubit-dissipation/amp/

Alice & Bob and ENS Lyon report a way to stabilize cat qubits with a steady voltage instead of a microwave drive. The companies say it could mean more compact quantum hardware that gives off less heat inside the cryostat. The results are in a preprint that has not been peer-reviewed.

## Key facts

- A SQUID biased with about one millionth of a volt couples a memory resonator to a lossy buffer resonator and exchanges photons between them.
- The reported two-photon exchange rate is 3 MHz, which the companies say beats any earlier microwave-pumped coupler.
- Changing the bias switches the device between one-, two- and four-photon processes, which could support four-component cat qubits.
- The approach is presented as a complement to the existing microwave-driven method, and four-photon operation remains a future goal.

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