For quantum error correction, if the error rate of our physical components is below a certain error threshold, we can decrease the overall computational error indefinitely by scaling up the code. To obtain the value of such a threshold, we need to simulate the quantum error correction circuit, which can only be done efficiently classically if there are only Pauli errors occurring in the circuit. Twirling is a technique that ‘twirl’ out the irregularity of an arbitrary error channel, turning it into a Pauli error channel. Hence, by applying twirling, we can efficiently simulate a quantum error correction circuit on a classical computer for any error models. Our paper describes how Pauli twirling works and how to do it efficiently.
The full paper can be found here.
