error mitigation
Correcting a quantum computer's answers afterwards, by calculation.
Error mitigation does not stop errors happening. It runs the program many times, often under deliberately changed noise, and calculates what the error-free answer would have been. It is how today's quantum experiments get usable results. Its price is extra shots on the machine. It is expected to stay useful even on early error-corrected machines.
Think of it as
Like correcting a bathroom scale you know reads 2 kg heavy: the scale stays wrong, but you can still work out your true weight.
Example
A team runs a chemistry circuit and gets a noisy answer. They run it again under raised noise, see how the answer shifts, and work back to an estimate of the noise-free value.
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