Syndrome

A quantum error correction simulator and game built on the rotated surface code, the same kind of code Google used in the Willow experiment.

• Inject errors into the qubits of a grid of distance 3, 5, 7 or 9 and look at the signals (the syndrome) they leave.
• Step by step: errors, defects, matching, correction and verdict, with pause and step back.
• The chart: the logical error rate for distances 3, 5 and 7, with its confidence intervals. It starts from curves that are already validated and refines them live in your browser. Two noise models: perfect measurements, or measurements that can fail.
• Challenge mode: you are the decoder. Draw a correction against the clock and compare it with the algorithm’s. Every puzzle can be shared with a link.

In English and Spanish. After the first visit it works offline.

Under study

A daily decoding puzzle: the same syndrome for everyone, every day. It is an idea, not a commitment: it has no date.

Open Syndrome

• What the Syndrome chart says

  Below a threshold, a larger code makes fewer logical errors. What Syndrome's chart plots, how to read it and where the curves cross.

• Method

  How we check that Syndrome computes the same as the reference software.