Removing leakage-induced correlated errors in superconducting quantum error correction
Abstract
Quantum computing can become scalable through error correction, but logical error rates only decrease with system size when physical errors are sufficiently uncorrelated. During computation, unused high energy levels of the qubits can become excited, creating leakage states that are long-lived and mobile. Particularly for superconducting transmon qubits, this leakage opens a path to errors that are correlated in space and time. Here, we report a reset protocol that returns a qubit to the ground state from all relevant higher level states. We test its performance with the bit-flip stabilizer code, a simplified version of the surface code for quantum error correction. We investigate the accumulation and dynamics of leakage during error correction. Using this protocol, we find lower rates of logical errors and an improved scaling and stability of error suppression with increasing qubit number. This demonstration provides a key step on the path towards scalable quantum computing.
Cite
@article{arxiv.2102.06131,
title = {Removing leakage-induced correlated errors in superconducting quantum error correction},
author = {M. McEwen and D. Kafri and Z. Chen and J. Atalaya and K. J. Satzinger and C. Quintana and P. V. Klimov and D. Sank and C. Gidney and A. G. Fowler and F. Arute and K. Arya and B. Buckley and B. Burkett and N. Bushnell and B. Chiaro and R. Collins and S. Demura and A. Dunsworth and C. Erickson and B. Foxen and M. Giustina and T. Huang and S. Hong and E. Jeffrey and S. Kim and K. Kechedzhi and F. Kostritsa and P. Laptev and A. Megrant and X. Mi and J. Mutus and O. Naaman and M. Neeley and C. Neill and M. Niu and A. Paler and N. Redd and P. Roushan and T. C. White and J. Yao and P. Yeh and A. Zalcman and Yu Chen and V. N. Smelyanskiy and John M. Martinis and H. Neven and J. Kelly and A. N. Korotkov and A. G. Petukhov and R. Barends},
journal= {arXiv preprint arXiv:2102.06131},
year = {2021}
}