Generating noise effects of relaxation

We learned in Chapter 10, Executing Circuits Using Qiskit Aer, that we can generate various noise models that are based on the configuration of a specified quantum computer. After the configuration information is extracted, we can then apply any one of an array of error functions to a simulator, which will reproduce similar error effects to what we would get from a quantum computer.

In this section, we will expand on that to learn how to execute test circuits and visualize the results from those tests. This will help us to understand how various noise models affect the results over time. The two effects we will review here are the two most common issues found in near-term quantum systems: relaxation and dephasing. These are critical errors as they can affect the quantum state information, which would result in erroneous responses.

Later on in this chapter, we will also look at readout errors, which is another common source that originates...