Entanglement genesis by ancilla-based parity measurement in 2D circuit QED

Authors :: Saira, O. -P.
Groen, J. P.
Cramer, J.
Meretska, M.
de Lange, G.
DiCarlo, L.
Source :: Phys. Rev. Lett. 112, 070502 (2014)
Publication Year :: 2013
Abstract: 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 non-demolition. Separate interaction and measurement steps allow commencing subsequent data qubit operations in parallel with ancilla measurement, offering time savings over continuous schemes.<br />Comment: 5 pages, 4 figures; supplemental material with 5 figures