| Autor: |
Chow JM; IBM T.J. Watson Research Center, Yorktown Heights, New York 10598, USA., Gambetta JM; IBM T.J. Watson Research Center, Yorktown Heights, New York 10598, USA., Magesan E; IBM T.J. Watson Research Center, Yorktown Heights, New York 10598, USA., Abraham DW; IBM T.J. Watson Research Center, Yorktown Heights, New York 10598, USA., Cross AW; IBM T.J. Watson Research Center, Yorktown Heights, New York 10598, USA., Johnson BR; Raytheon BBN Technologies, Cambridge, Massachusetts 02138, USA., Masluk NA; IBM T.J. Watson Research Center, Yorktown Heights, New York 10598, USA., Ryan CA; Raytheon BBN Technologies, Cambridge, Massachusetts 02138, USA., Smolin JA; IBM T.J. Watson Research Center, Yorktown Heights, New York 10598, USA., Srinivasan SJ; IBM T.J. Watson Research Center, Yorktown Heights, New York 10598, USA., Steffen M; IBM T.J. Watson Research Center, Yorktown Heights, New York 10598, USA. |
| Abstrakt: |
With favourable error thresholds and requiring only nearest-neighbour interactions on a lattice, the surface code is an error-correcting code that has garnered considerable attention. At the heart of this code is the ability to perform a low-weight parity measurement of local code qubits. Here we demonstrate high-fidelity parity detection of two code qubits via measurement of a third syndrome qubit. With high-fidelity gates, we generate entanglement distributed across three superconducting qubits in a lattice where each code qubit is coupled to two bus resonators. Via high-fidelity measurement of the syndrome qubit, we deterministically entangle the code qubits in either an even or odd parity Bell state, conditioned on the syndrome qubit state. Finally, to fully characterize this parity readout, we develop a measurement tomography protocol. The lattice presented naturally extends to larger networks of qubits, outlining a path towards fault-tolerant quantum computing. |
