2
$\begingroup$

Currently I am building up quantum error correction code with stim code.

According to this paper [https://journals.aps.org/pra/abstract/10.1103/PhysRevA.86.032324], I need to make an error channel that includes CNOT operators and 2 qubit Pauli operator set.

for example, Attempting to perform CNOT operator, but instead appling X_1 X_2 operator with some probability p.

Is there any way I can make this kind of error channel in stim code ?

$\endgroup$

1 Answer 1

2
$\begingroup$

You can use CORRELATED_ERROR to introduce probabilistic Pauli products.

CNOT 0 1
CORRELATED_ERROR(0.001) X0 X1

You can also use DEPOLARIZE2, which includes equal portions of all 15 possible two qubit Pauli errors, and PAULI_CHANNEL_2, which lets you specify 15 float parameters one for each of the two qubit Pauli error cases.

Note that you can't apply these errors instead of a CNOT. Stim doesn't support conditional or probabilistic Clifford operations. You can only apply them in addition to a CNOT. This is compatible with the paper you cited; I'm not sure where you got the idea you needed to not do the CNOT instead of perturb the CNOT.

$\endgroup$
2
  • $\begingroup$ Thank you so much. It was informative. The paper says, attempting to perform a measure qubit-data qubit CNOT, but instead performing one of the two-qubit operations I ⊗ X, I⊗Y, I⊗Z, X⊗I, X⊗X, X⊗Y, X⊗Z, Y⊗I, Y⊗X, Y⊗Y, Y⊗Z, Z⊗I, Z⊗X, Z⊗Y, or Z⊗Z each with probability p/15. So I thought this means an error channel that includes CNOT operators and 2 qubit Pauli operator set. But like you mentioned, Maybe I will try to perturb the CNOT. $\endgroup$ Apr 8, 2022 at 10:44
  • 1
    $\begingroup$ @YounghunKim That error you described from the paper is a DEPOLARIZE2(p) error. $\endgroup$ Apr 8, 2022 at 17:01

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.