Readout error in IBM quantum experience processor

Question

Is there a section on the IBM website that shows information about the readout error for the devices of quantum experience? I have only seen the errors for single-qubit (U2) and CNOT gates but nothing involving measurements.

If not, is there any suggestion about how to measure it? The only thing that comes to my mind is to run the ground state because any circuit would mix readout with gate errors. But I think that the resulting noise might as well be due to other factors like imperfect preparation of the ground state.

Answer 1

Go to the first page in IBM Q web interface, click on a quantum processor you are interested in and finally click on link Download calibration.

You will see a table (CSV file) containing decoherence times $T1$, $T2$, read-out, single-qubit $U2$ error rate and CNOT error rate.

Answer 2

You can also see this directly in Qiskit. To see the cals visually you can do:

from qiskit import IBMQ
from qiskit.visualization import plot_error_map
provider = IBMQ.load_account()
backend = provider.backends.ibmq_rome

plot_error_map(backend)