Quantum codes correct errors even with qubit loss or gain

Researchers at the University of Sheffield have shown that permutation-invariant quantum error-correcting codes can handle synchronisation errors, where qubits are lost from or added to a register. The work establishes an equivalence between insertions and deletions in this setting, widening the class of errors that quantum codes can correct.

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What this could mean

0–2 yearsPlausible
This could let photonic quantum systems treat photon loss as a correctable deletion error rather than a fatal fault, reducing the need for postselection.
Permutation-invariant codes fit platforms where qubits are indistinguishable, such as dual-rail photonic encodings; if the insertion/deletion equivalence maps onto bosonic loss channels, decoder designers could use it within current hardware iterations to recover from losses that now abort computations.

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