Demonstrating a long-coherence dual-rail erasure qubit using tunable transmons

  1. Harry Levine,
  2. Arbel Haim,
  3. Jimmy S.C. Hung,
  4. Nasser Alidoust,
  5. Mahmoud Kalaee,
  6. Laura DeLorenzo,
  7. E. Alex Wollack,
  8. Patricio Arrangoiz-Arriola,
  9. Amirhossein Khalajhedayati,
  10. Yotam Vaknin,
  11. Aleksander Kubica,
  12. Aashish A. Clerk,
  13. David Hover,
  14. Fernando Brandão,
  15. Alex Retzker,
  16. and Oskar Painter
Quantum error correction with erasure qubits promises significant advantages over standard error correction due to favorable thresholds for erasure errors. To realize this advantagein practice requires a qubit for which nearly all errors are such erasure errors, and the ability to check for erasure errors without dephasing the qubit. We experimentally demonstrate that a „dual-rail qubit“ consisting of a pair of resonantly-coupled transmons can form a highly coherent erasure qubit, where the erasure error rate is given by the transmon T1 but for which residual dephasing is strongly suppressed, leading to millisecond-scale coherence within the qubit subspace. We show that single-qubit gates are limited primarily by erasure errors, with erasure probability perasure=2.19(2)×10−3 per gate while the residual errors are ∼40 times lower. We further demonstrate mid-circuit detection of erasure errors while introducing <0.1% dephasing error per check. Finally, we show that the suppression of transmon noise allows this dual-rail qubit to preserve high coherence over a broad tunable operating range, offering an improved capacity to avoid frequency collisions. This work establishes transmon-based dual-rail qubits as an attractive building block for hardware-efficient quantum error correction.[/expand]

Loss channels affecting lithium niobate phononic crystal resonators at cryogenic temperature

  1. E. Alex Wollack,
  2. Agnetta Y. Cleland,
  3. Patricio Arrangoiz-Arriola,
  4. Timothy P. McKenna,
  5. Rachel G. Gruenke,
  6. Rishi N. Patel,
  7. Wentao Jiang,
  8. Christopher J. Sarabalis,
  9. and Amir H. Safavi-Naeini
We investigate the performance of microwave-frequency phononic crystal resonators fabricated on thin-film lithium niobate for integration with superconducting quantum circuits. For

Cryogenic microwave-to-optical conversion using a triply-resonant lithium niobate on sapphire transducer

  1. Timothy P. McKenna,
  2. Jeremy D. Witmer,
  3. Rishi N. Patel,
  4. Wentao Jiang,
  5. Raphaël Van Laer,
  6. Patricio Arrangoiz-Arriola,
  7. E. Alex Wollack,
  8. Jason F. Herrmann,
  9. and Amir H. Safavi-Naeini
Quantum networks are likely to have a profound impact on the way we compute and communicate in the future. In order to wire together superconducting quantum processors over kilometer-scale

Electric fields for light: Propagation of microwave photons along a synthetic dimension

  1. Nathan R. A. Lee,
  2. Marek Pechal,
  3. E. Alex Wollack,
  4. Patricio Arrangoiz-Arriola,
  5. Zhaoyou Wang,
  6. and Amir H. Safavi-Naeini
The evenly-spaced modes of an electromagnetic resonator are coupled to each other by appropriate time-modulation, leading to dynamics analogous to those of particles hopping between