Mitigating readout errors

Ignis has measurement filters that can be used to mitigate various types of errors, such as measurements and tensors.

The measurement calibration is what we will use to mitigate measurement errors in this section. The process begins by first generating a list of circuits, where each circuit represents each of all the possible states of the qubits specified, then executing the circuits on an ideal simulator, the results of which we will then pass into a measurement filter. The measurement filter will then be used to mitigate the measurement errors. In the following example, we will first run the circuits on a simulator without any noise models. Then, we will create a noise model that will be applied to all the qubits of the simulator. Then we will execute the circuits on the noisy backend device, where we will then apply the measurement filter to mitigate the errors as best we can. Finally, we will view the results of the measurement filter and compare them...