I have a beginner question regarding CNOT-Gates on IBM Quantum.
Assuming the following simple circuit:
qreg q; creg c; h q; cx q,q; measure q -> c; measure q -> c;
Ideally, we would expect a probability of 50% for |00> and |11> and 0% for |10> and |01>, respectively. Now, if I simulate the circuit I get something like ~52 vs 48% for the entangled states; and |10> and |01> is still 0%. However, if I run the circuit on e.g. ibmq_manila there is a probability of some percentage to also find |10> and |01>. In total P(|10>) + P(|01>) is approx. 5% in my experiment. Is this simply the CNOT error rate?
Is there a way to account for these errors? Do they depend on which Qubits I am using?