Quantum error correction at QCE26 became a race for the decoder

This guide follows 46 error-correction talks at IEEE Quantum Week 2026 in Toronto. Most of them dwelt on the classical machines that must keep up with the qubits. On the afternoon of Monday 14 September, at the end of a tutorial in Room 716A of the Metro Toronto Convention Centre, Daniel Bulmash of IQM put up a sum. A useful quantum computer might hold 10,000 logical qubits, the reliable qubits a program sees. Each needs about 50 checks a microsecond. That makes a stream of 500 gigabits a second, and some ordinary computer has to read all of it, decide what went wrong and send back a fix before the next microsecond starts. The programs that do that job are called quantum error correction decoders. That stream, and the clock it runs against, is what quantum error correction is now about. Qubits fail often. Even good hardware gets about one step in a thousand wrong, while a program that could break RSA encryption needs about a trillion steps without a slip. So error correction spreads each logical qubit across many physical qubits and checks them over and over. A classical program called a decoder reads which checks failed and works…