In c , we include a Yj measurement for logical qubit j = 1, 2 to measure logical operators of the form Yj , YjXk and YjZk with k j and k = 1, 2, where we take an appropriate choice of R . The Yj operator is measured twice to identify the occurrence of measurement errors. Operators Yj are supported on three of the data qubits and can therefore be read out with an appropriate modification of the circuit shown in Fig. 1 .
