Error-mitigated simulation of quantum many-body scars on quantum computers with pulse-level control
Error-mitigated simulation of quantum many-body scars on quantum computers with pulse-level control
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DOI：
10.1103/physrevresearch.4.043027
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发表时间：
2022-10-13
影响因子：
4.2
通讯作者：
Iadecola, Thomas
中科院分区：
文献类型：
--
作者：
Chen, I. -Chi;Burdick, Benjamin;Iadecola, Thomas
量子多体伤疤是一种有趣的动力学机制，在这种机制中，量子系统在特定的初始态下表现出相干动力学和长程关联。我们使用这种相干性和多体相关性的组合，通过使用它们来模拟多达19个站点的混合场伊辛链中的反铁磁初始状态的动力学，来对当今量子计算设备的性能进行基准测试。除了计算局部观测量的动力学，我们还计算了Loschirst回声和一个非平凡的不等时连接的相关函数，见证了远程多体相关性的疤痕动力学。我们发现连贯的动态持续超过40特罗特步骤，即使在存在各种来源的错误。为了获得这些结果，我们利用各种误差缓解技术，包括噪声剪裁，零噪声外推，动态解耦，和物理动机后选择的测量结果。至关重要的是，我们还发现，使用脉冲电平控制来实现Ising相互作用比基于标准控制的NOT编译这种相互作用有了实质性的改进。我们的研究结果表明，错误缓解技术和脉冲电平控制探测多体相干性和相关性对当今量子硬件的影响。
Quantum many-body scars are an intriguing dynamical regime in which quantum systems exhibit coherent dy-namics and long-range correlations when prepared in certain initial states. We use this combination of coherence and many-body correlations to benchmark the performance of present-day quantum computing devices by using them to simulate the dynamics of an antiferromagnetic initial state in mixed-field Ising chains of up to 19 sites. In addition to calculating the dynamics of local observables, we also calculate the Loschmidt echo and a nontrivial unequal-time connected correlation function that witnesses long-range many-body correlations in the scarred dynamics. We find coherent dynamics to persist over up to 40 Trotter steps even in the presence of various sources of error. To obtain these results, we leverage a variety of error-mitigation techniques including noise tailoring, zero-noise extrapolation, dynamical decoupling, and physically motivated postselection of measurement results. Crucially, we also find that using pulse-level control to implement the Ising interaction yields a substantial improvement over the standard controlled -NOT-based compilation of this interaction. Our results demonstrate the power of error-mitigation techniques and pulse-level control to probe many-body coherence and correlation effects on present-day quantum hardware.