Print Email Facebook Twitter Chip-to-chip entanglement of transmon qubits using engineered measurement fields Title Chip-to-chip entanglement of transmon qubits using engineered measurement fields Author Dickel, C. (TU Delft QCD/DiCarlo Lab) Wesdorp, J.J. (TU Delft Applied Sciences) Langford, N.K. (TU Delft QCD/DiCarlo Lab; University of Technology Sydney) Peiter, S.R. Sagastizabal, R.E. (TU Delft QCD/DiCarlo Lab) Bruno, A. (TU Delft QCD/DiCarlo Lab) Criger, D.B. (TU Delft QCD/Terhal Group) Motzoi, F. (Aarhus University) DiCarlo, L. (TU Delft QCD/DiCarlo Lab; TU Delft QN/DiCarlo Lab) Faculty Applied Sciences Date 2018 Abstract While the on-chip processing power in circuit QED devices is growing rapidly, an open challenge is to establish high-fidelity quantum links between qubits on different chips. Here, we show entanglement between transmon qubits on different cQED chips with 49% concurrence and 73% Bell-state fidelity. We engineer a half-parity measurement by successively reflecting a coherent microwave field off two nearly identical transmon-resonator systems. By ensuring the measured output field does not distinguish |01) from |10), unentangled superposition states are probabilistically projected onto entangled states in the odd-parity subspace. We use in situ tunability and an additional weakly coupled driving field on the second resonator to overcome imperfect matching due to fabrication variations. To demonstrate the flexibility of this approach, we also produce an even-parity entangled state of similar quality, by engineering the matching of outputs for the |00) and |11) states. The protocol is characterized over a range of measurement strengths using quantum state tomography showing good agreement with a comprehensive theoretical model. To reference this document use: http://resolver.tudelft.nl/uuid:a2621983-e7a9-497a-9019-17bf548e9250 DOI https://doi.org/10.1103/PhysRevB.97.064508 ISSN 2469-9950 Source Physical Review B, 97 (6) Part of collection Institutional Repository Document type journal article Rights © 2018 C. Dickel, J.J. Wesdorp, N.K. Langford, S.R. Peiter, R.E. Sagastizabal, A. Bruno, D.B. Criger, F. Motzoi, L. DiCarlo Files PDF PhysRevB.97.064508.pdf 4.04 MB Close viewer /islandora/object/uuid:a2621983-e7a9-497a-9019-17bf548e9250/datastream/OBJ/view