Entanglement Genesis by Ancilla-Based Parity Measurement in 2D Circuit QED
O.-P. Saira, Joost Groen, Julia Cramer, Maryna L. Meretska, G. de Lange, L. DiCarlo · Physical Review Letters · 2014
We present an indirect two-qubit parity meter in planar circuit quantum electrodynamics, realized by discrete interaction with an ancilla and a subsequent projective ancilla measurement with a dedicated, dispersively coupled resonator. Quantum process tomography and successful entanglement by measurement demonstrate that the meter is intrinsically quantum nondemolition. Separate interaction and measurement steps allow the execution of subsequent data-qubit operations in parallel with ancilla measurement, offering time savings over continuous schemes.