Boosting Computational Power through Spatial Multiplexing in Quantum Reservoir Computing
Boosting Computational Power through Spatial Multiplexing in Quantum Reservoir Computing
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DOI：
10.1103/physrevapplied.11.034021
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发表时间：
2019-03-08
影响因子：
4.6
通讯作者：
Kitagawa, Masahiro
中科院分区：
文献类型：
--
作者：
Nakajima, Kohei;Fujii, Keisuke;Kitagawa, Masahiro
量子水库计算提供了一个框架，利用量子系统的自然动力学作为计算资源。它可以实现实时信号处理，并解决一般的时间机器学习问题，这需要内存和最近的输入流的非线性映射，使用量子动力学在计算优势区域，其中系统的经典模拟是棘手的。核磁共振自旋系综系统是这种物理实现的现实候选者之一，目前在实验室中可用。在本文中，考虑到这些现实的实验约束，实现的框架，我们引入了一个计划，我们称之为空间复用技术，有效地提高了平台的计算能力。这种技术利用了不相交动力学，它起源于由共同输入流并行驱动的多个不同的量子系统。因此，与设计单个大型量子系统以增加计算节点的量子比特数量不同，可以从多个但小的量子系统中制备大量量子比特，这在实验室实验中易于操作。我们数值上证明了该技术的有效性，使用几个基准任务，并定量研究其规格，有效性范围和限制的细节。
Quantum reservoir computing provides a framework for exploiting the natural dynamics of quantum systems as a computational resource. It can implement real-time signal processing and solve temporal machine-learning problems in general, which requires memory and nonlinear mapping of the recent input stream using the quantum dynamics in the computational supremacy region, where the classical simulation of the system is intractable. A nuclear-magnetic-resonance spin-ensemble system is one of the realistic candidates for such physical implementations, which is currently available in laboratories. In this paper, considering these realistic experimental constraints for implementing the framework, we introduce a scheme, which we call a spatial multiplexing technique, to effectively boost the computational power of the platform. This technique exploits disjoint dynamics, which originate from multiple different quantum systems driven by common input streams in parallel. Accordingly, unlike designing a single large quantum system to increase the number of qubits for computational nodes, it is possible to prepare a huge number of qubits from multiple but small quantum systems, which are operationally easy to handle in laboratory experiments. We numerically demonstrate the effectiveness of the technique using several benchmark tasks and quantitatively investigate its specifications, range of validity, and limitations in detail.