Griffiths-McCoy singularity on the diluted Chimera graph: Monte Carlo simulations and experiments on quantum hardware
Griffiths-McCoy singularity on the diluted Chimera graph: Monte Carlo simulations and experiments on quantum hardware
复制标题
稀释 Chimera 图上的 Griffiths-McCoy 奇点：量子硬件上的蒙特卡罗模拟和实验
DOI：
--
复制
发表时间：
2020
期刊：
影响因子：
--
通讯作者：
H. Katzgraber
中科院分区：
文献类型：
--
作者：
Kohji Nishimura;H. Nishimori;H. Katzgraber
格里菲斯-麦考伊奇点是低维无序量子自旋系统的一种现象特征，其中磁化率即使在顺磁相内也表现出作为外部场的函数的奇异行为。我们通过量子蒙特卡罗模拟和在用作量子模拟器的 D-Wave 量子退火器上进行大量实验，研究是否在准二维稀释 Chimera 图上具有无序铁磁相互作用的横向场 Ising 模型中观察到这种现象。通过量子蒙特卡罗模拟，找到了顺磁相中格里菲斯-麦考伊奇点存在的证据。由于模拟量子设备中固有的噪声和误差，量子硬件上的实验方法产生的结果不太明确，但仍然可以解释为与蒙特卡罗情况中格里菲斯-麦考伊奇点的存在相一致。这是第一个基于模拟量子模拟器来研究无序量子自旋系统中 Griffiths-McCoy 奇点的微妙现象的实验方法，通过该方法我们阐明了 D-Wave 量子退火器作为量子模拟器的能力和局限性。
The Griffiths-McCoy singularity is a phenomenon characteristic of low-dimensional disordered quantum spin systems, in which the magnetic susceptibility shows singular behavior as a function of the external field even within the paramagnetic phase. We study whether this phenomenon is observed in the transverse-field Ising model with disordered ferromagnetic interactions on the quasi-two-dimensional diluted Chimera graph both by quantum Monte Carlo simulations and by extensive experiments on the D-Wave quantum annealer used as a quantum simulator. From quantum Monte Carlo simulations, evidence is found for the existence of the Griffiths-McCoy singularity in the paramagnetic phase. The experimental approach on the quantum hardware produces results that are less clear-cut due to the intrinsic noise and errors in the analog quantum device but can nonetheless be interpreted to be consistent with the existence of the Griffiths-McCoy singularity as in the Monte Carlo case. This is the first experimental approach based on an analog quantum simulator to study the subtle phenomenon of Griffiths-McCoy singularities in a disordered quantum spin system, through which we have clarified the capabilities and limitations of the D-Wave quantum annealer as a quantum simulator.