论文标题
在带有随机电路的嘈杂中间量子量子设备上模拟流体动力学
Simulating hydrodynamics on noisy intermediate-scale quantum devices with random circuits
论文作者
论文摘要
在最近的一个里程碑实验中，Google的加工机Sycamore通过（伪）随机电路的输出进行了抽样，预示了“量子至上”的时代。我们表明，这种随机电路提供了量身定制的构件，用于在嘈杂的中间量子量子（NISQ）设备上模拟量子多体系统。具体而言，我们提出了一种由随机电路组成的算法，然后是trotterized Hamiltonian时间演化，以研究流体动力学并提取线性响应方案中的传输系数。我们通过模拟一维量子自旋系统中的时空相关函数的堆积来证明算法，在此我们特别仔细研究了任何现实实现中存在错误的不可避免的影响。重要的是，我们发现相关性的流体动力缩放相对于猪跑步的大小高度稳健，这为达到少量门的非平凡时间尺度打开了门。尽管显示随机电路中的错误是无关紧要的，但我们此外，我们揭示了在嘈杂的时间演变中可以获得有意义的结果，并且在近期硬件上可以达到错误率。我们的工作强调了除了抽象抽样任务之外的NISQ设备上随机电路的实际相关性。
In a recent milestone experiment, Google's processor Sycamore heralded the era of "quantum supremacy" by sampling from the output of (pseudo-)random circuits. We show that such random circuits provide tailor-made building blocks for simulating quantum many-body systems on noisy intermediate-scale quantum (NISQ) devices. Specifically, we propose an algorithm consisting of a random circuit followed by a trotterized Hamiltonian time evolution to study hydrodynamics and to extract transport coefficients in the linear response regime. We numerically demonstrate the algorithm by simulating the buildup of spatiotemporal correlation functions in one- and two-dimensional quantum spin systems, where we particularly scrutinize the inevitable impact of errors present in any realistic implementation. Importantly, we find that the hydrodynamic scaling of the correlations is highly robust with respect to the size of the Trotter step, which opens the door to reach nontrivial time scales with a small number of gates. While errors within the random circuit are shown to be irrelevant, we furthermore unveil that meaningful results can be obtained for noisy time evolutions with error rates achievable on near-term hardware. Our work emphasizes the practical relevance of random circuits on NISQ devices beyond the abstract sampling task.
