Measuring the parity of an N-qubit state.
We present a scheme for a projective measurement of the parity operator Pz = Product(N)i=1 sigma(i)z of N qubits. Our protocol uses a single ancillary qubit, or a probe qubit, and involves manipulations of the total spin of the N qubits without requiring individual addressing. We illustrate our protocol in terms of an experimental implementation with atomic ions in a two-zone linear Paul trap, and further discuss its extensions to several more general cases.
Zeng
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Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Zhou
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You
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