RQC Seminar

56th RQC Seminar

• Speaker

  Dr. Yosuke Ueno
  ( Superconducting Quantum Computing System Research Unit )

• Date

  15:00-16:00, June 28th, 2023 (Wednesday)

• Venue

  Hybrid(ZOOM・ Wako Welfare and Conf. 2F Large Meeting Room)

• Title

  Online surface code decoder with a superconducting circuit

• Inquiries

  rqc_info[at]ml.riken.jp

Abstract
Quantum Error Correction (QEC) is essential for quantum computing to mitigate the effect of errors on qubits, and Surface code (SC) is one of the most promising QEC methods. Decoding SCs is the most computational expensive task in the control device of quantum computers (QCs), and many works focus on accurate decoding algorithms for SCs. Practical QCs also require low-latency decoding because slow decoding leads to the accumulation of errors on qubits, resulting in logical failures. For QCs with superconducting qubits, a practical decoder must be very power-efficient in addition to high accuracy and low latency. In order to reduce the hardware complexity of QC, we are supposed to decode SCs in a cryogenic environment with a limited power budget, where superconducting qubits operate.
In this work, we propose the concept of online-QEC, where both the measurement and decoding processes of QEC are performed simultaneously to achieve low-latency SC decoding. Then, we propose decoding algorithms based on the concept and their hardware implementations with SFQ-based superconducting digital circuits to achieve high-speed and low-power decoders.