Detecting bit-flip errors in a logical qubit using stabilizer measurements

Quantum data are susceptible to decoherence induced by the environment and to errors in the hardware processing it. A future fault-tolerant quantum computer will use quantum error correction to actively protect against both. In the smallest error correction codes, the information in one logical qubit is encoded in a two-dimensional subspace of a larger Hilbert space of multiple physical qubits. For each code, a set of non-demolition multi-qubit measurements, termed stabilizers, can discretize and signal physical qubit errors without collapsing the encoded information. Here using a five-qubit superconducting processor, we realize the two parity measurements comprising the stabilizers of the three-qubit repetition code protecting one logical qubit from physical bit-flip errors. While increased physical qubit coherence times and shorter quantum error correction blocks are required to actively safeguard the quantum information, this demonstration is a critical step towards larger codes based on multiple parity measurements.

Authors

Diego Ristè; Stefano Poletto; M.-Z. Huang; Alessandro Bruno; Visa Vesterinen; O.-P. Saira; L. DiCarlo

Published

Apr 29, 2015

Journal or venue

Nature Communications

DOI

10.1038/ncomms7983

Paper type

journal article

Source

Openalex