Real-time processing of stabilizer measurements in a bit-flip code

Abstract

Although qubit coherence times and gate fidelities are continuously improving, logical encoding is essential to achieve fault tolerance in quantum computing. In most encoding schemes, correcting or tracking errors throughout the computation is necessary to implement a universal gate set without adding significant delays in the processor. Here, we realize a classical control architecture for the fast extraction of errors based on multiple cycles of stabilizer measurements and subsequent correction. We demonstrate its application on a minimal bit-flip code with five transmon qubits, showing that real-time decoding and correction based on multiple stabilizers is superior in both speed and fidelity to repeated correction based on individual cycles. Furthermore, the encoded qubit can be rapidly measured, thus enabling conditional operations that rely on feed forward, such as logical gates. This co-processing of classical and quantum information will be crucial in running a logical circuit at its full speed to outpace error accumulation.

Document Details

Document Type
Pub Defense Publication
Publication Date
Aug 21, 2020
Source ID
10.1038/s41534-020-00304-y

Entities

People

  • Brian Donovan
  • Diego Ristè
  • Luke C. G. Govia
  • Markus Brink
  • Nicholas Bronn
  • Spencer D. Fallek
  • Thomas Ohki
  • William D. Kalfus

Organizations

  • Intelligence Advanced Research Projects Activity

Tags

Readers

  • Geodesy
  • Neural Network Machine Learning.
  • Quantum Dot Semiconductor Device Photonics and Graphene Optoelectronic Materials and THz Physics.

Technology Areas

  • Quantum Computing