Robust Error Accumulation Suppression for Quantum Circuits
We present a robust error accumulation suppression (REAS) technique to manage
errors in quantum computers. Our method reduces the accumulation of errors in
any quantum circuit composed of single- or two-qubit gates expressed as $e^{-i
\sigma\theta }$ for Pauli operators $\sigma$ and $\theta \in [0,\pi)$, which
forms a universal gate set. For coherent errors -- which include gate
overrotation and crosstalk -- we demonstrate a reduction of the error scaling
in an $L$-depth circuit from $O(L)$ to $O(\sqrt{L})$. This asymptotic error
suppression behavior can be proven in a regime where all gates -- including
those constituting the error-suppressing protocol itself -- are noisy. Going
beyond coherent errors, we derive the general form of decoherence noise that
can be suppressed by REAS. Lastly, we experimentally demonstrate the
effectiveness of our approach regarding realistic errors using 100-qubit
circuits with up to 64 two-qubit gate layers on IBM Quantum processors.
Tatsuki Odake Philip Taranto Nobuyuki Yoshioka Toshinari Itoko Kunal Sharma Antonio Mezzacapo Mio Murao