Demonstration of qubit operations below a rigorous fault tolerance threshold with
gate set tomography
#MMPMID28198466
Blume-Kohout R
; Gamble JK
; Nielsen E
; Rudinger K
; Mizrahi J
; Fortier K
; Maunz P
Nat Commun
2017[Feb]; 8
(?): ? PMID28198466
show ga
Quantum information processors promise fast algorithms for problems inaccessible
to classical computers. But since qubits are noisy and error-prone, they will
depend on fault-tolerant quantum error correction (FTQEC) to compute reliably.
Quantum error correction can protect against general noise if-and only if-the
error in each physical qubit operation is smaller than a certain threshold. The
threshold for general errors is quantified by their diamond norm. Until now,
qubits have been assessed primarily by randomized benchmarking, which reports a
different error rate that is not sensitive to all errors, and cannot be compared
directly to diamond norm thresholds. Here we use gate set tomography to
completely characterize operations on a trapped-Yb(+)-ion qubit and demonstrate
with greater than 95% confidence that they satisfy a rigorous threshold for FTQEC
(diamond norm ?6.7 × 10(-4)).