论文标题
分层解码以减少量子计算的硬件要求
Hierarchical decoding to reduce hardware requirements for quantum computing
论文作者
论文摘要
为了将量子硬件扩展到实用应用程序，需要进行广泛的量子误差校正。结果，需要大量的解码硬件来处理不断检测和纠正数百万个驱动计算的物理量子的错误所需的巨大数据。 Shor's算法的最新高度优化版本以将2,048位整数的因素实现，将需要更多的7 tbit/s带宽，以实现量子误差校正和多达20,000个解码单元的唯一目的。为了减少解码硬件要求，我们提出了一个基于表面代码的易耐故障量子计算体系结构，该构造具有便宜的硬击解解码器The Lazy Decoder，并结合了一个复杂的复杂错误配置的复杂解码单元。假设提供了足够好的QUBIT，我们的设计通过几个数量级降低了解码硬件的要求。给定的量子和量子门，具有物理错误率$ p = 10^{ - 4} $，懒惰解码器将带宽要求和解码单元的数量降低了50x。提供了非常好的Qubits，并带有错误率$ p = 10^{ - 5} $，我们得益于懒惰解码器的带宽和解码硬件的1,500倍。最后，懒惰解码器可以用作解码器加速器。我们的模拟显示了Union-Find解码器的10倍加速和最小重量的最小重量匹配解码器的50倍加速。
Extensive quantum error correction is necessary in order to scale quantum hardware to the regime of practical applications. As a result, a significant amount of decoding hardware is necessary to process the colossal amount of data required to constantly detect and correct errors occurring over the millions of physical qubits driving the computation. The implementation of a recent highly optimized version of Shor's algorithm to factor a 2,048-bits integer would require more 7 TBit/s of bandwidth for the sole purpose of quantum error correction and up to 20,000 decoding units. To reduce the decoding hardware requirements, we propose a fault-tolerant quantum computing architecture based on surface codes with a cheap hard-decision decoder, the lazy decoder, combined with a sophisticated decoding unit that takes care of complex error configurations. Our design drops the decoding hardware requirements by several orders of magnitude assuming that good enough qubits are provided. Given qubits and quantum gates with a physical error rate $p=10^{-4}$, the lazy decoder drops both the bandwidth requirements and the number of decoding units by a factor 50x. Provided very good qubits with error rate $p=10^{-5}$, we obtain a 1,500x reduction in bandwidth and decoding hardware thanks to the lazy decoder. Finally, the lazy decoder can be used as a decoder accelerator. Our simulations show a 10x speed-up of the Union-Find decoder and a 50x speed-up of the Minimum Weight Perfect Matching decoder.
