# Which algorithms use amplitude of the measurement of a cricuit?

So my question is motivated by noise. If we have a circuit and we get multiple results. In which algorithms does it matter to use which amplitude the results have? For example, when we measure our circuit we get two states which have a higher amplitude than any other states. And let's say the probability of these two states is 0.4 each. The rest of the probability is just noise. On the other hand, we simulate our result and the measured value is 0.5. Does this make a difference? we already knew that the states with the measured value of 0.4 were the solution to our algorithm. So why bother for example with error mitigation?

I hope I got my point across. Maybe I need some help with the wording of my question.

• It's not clear what you mean by "when we measure our circuit we get two states which have a higher amplitude than any other state". When you measure the circuit you collapse your wavefunction to only one state (in the computational basis). Are you saying that you can simulate your circuit to actually deduce the amplitudes? Or are you running your circuit on a real, live quantum computer? I'd consider revising your question further. Commented Jul 17, 2023 at 1:11