Measuring the parity of an $N$-qubit state

B. Zeng, D. L. Zhou, L. You

We present a scheme for a projective measurement of the parity operator $P_z={\prod }_{i=1}^N{\sigma }_z^{(i)}$ of $N$-qubits. Our protocol uses a single ancillary qubit, or a probe qubit, a…