Protecting a bosonic qubit with autonomous quantum error correction.

To build a universal quantum computer from fragile physical qubits, effective implementation of quantum error correction (QEC) is an essential requirement and a central challenge. Existing demonstrations of QEC are based on an active schedule of error-syndrome measurements and adaptive recovery operations that are hardware intensive and prone to introducing and propagating errors. In principle, QEC can be realized autonomously and continuously by tailoring dissipation within the quantum system, but so far it has remained challenging to achieve the specific form of dissipation required to counter the most prominent errors in a physical platform.