Probing qubit memory errors at the part-per-million level

Journal article

Robust qubit memory is essential for quantum computing, both for near-term devices operating without error correction, and for the long-term goal of a fault-tolerant processor. We directly measure the memory error ε_m for a ⁴³Ca⁺ trapped-ion qubit in the small-error regime and find ε_m<10⁻⁴ for storage times t ≲ 50  ms. This exceeds gate or measurement times by three orders of magnitude. Using randomized benchmarking, at t = 1  ms we measure ε_m=1.2(7)×10⁻⁶, around ten times smaller than that extrapolated from the T^∗₂ time, and limited by instability of the atomic clock reference used to benchmark the qubit.

Authors: Sepiol, M; Hughes, A; Tarlton, J; Nadlinger, D; Ballance, T

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: American Physical Society
• Journal: Physical Review Letters
• Volume: 123
• Issue: 11
• Article number: 110503
• Publication date: 2019-09-13
• Acceptance date: 2019-08-11
• DOI: 10.1103/physrevlett.123.110503
• EISSN: 1079-7114
• ISSN: 0031-9007
• Language: English
• Keywords: quantum information with trapped ions; quantum information architectures and platforms; quantum memories; quantum computation; quantum error correction; quantum control