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arXiv · 2103.14209

QECOOL: On-Line Quantum Error Correction with a Superconducting Decoder for Surface Code

Yosuke Ueno·Masaaki Kondo·Masamitsu Tanaka·Yasunari Suzuki·Yutaka Tabuchi
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Abstract

Due to the low error tolerance of a qubit, detecting and correcting errors on it is essential for fault-tolerant quantum computing. Surface code (SC) associated with its decoding algorithm is one of the most promising quantum error correction (QEC) methods. % One of the challenges of QEC is its high complexity and computational demand. QEC needs to be very power-efficient since the power budget is limited inside of a dilution refrigerator for superconducting qubits by which one of the most successful quantum computers (QCs) is built. In this paper, we propose an online-QEC algorithm and its hardware implementation with SFQ-based superconducting digital circuits. We design a key building block of the proposed hardware with an SFQ cell library and evaluate it by the SPICE-level simulation. Each logic element is composed of about 3000 Josephson junctions and power consumption is about 2.78 uW when operating with 2 GHz clock frequency which meets the required decoding speed. Our decoder is simulated on a quantum error simulator for code distances 5 to 13 and achieves a 1.0% accuracy threshold.

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Yosuke Ueno, Masaaki Kondo, Masamitsu Tanaka, Yasunari Suzuki, Yutaka Tabuchi. 2021-03-26. QECOOL: On-Line Quantum Error Correction with a Superconducting Decoder for Surface Code. https://doi.org/10.1109/dac18074.2021.9586326

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