Accurately computing the electronic properties of a quantum ring
Accurately computing the electronic properties of a quantum ring
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DOI：
10.1038/s41586-021-03576-2
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发表时间：
2021-06-24
期刊：
影响因子：
64.8
通讯作者：
Smelyanskiy, V.
中科院分区：
文献类型：
--
作者：
Neill, C.;McCourt, T.;Smelyanskiy, V.
研究凝聚态系统的一种有前途的方法是在工程量子平台上模拟它们（1-4）。然而，迄今为止，还没有达到优于经典方法所需的精度。在这里，使用18个超导量子比特，我们提供了一个精确的凝聚态模拟器的实验蓝图，并演示了如何研究基本的电子特性。我们通过重建一维线的单粒子能带结构来对基础方法进行基准测试。我们表现出几乎完全缓解的退相干和读出误差，并测量该线的能量本征值的误差约为0.01拉德，而典型的能量尺度是1拉德的顺序。通过突出傅立叶变换的鲁棒性，包括以10（-4）rad的统计不确定性解析本征能量的能力，来深入了解该算法的保真度。我们还综合了磁通量和无序局部势，这是凝聚态系统的两个关键原则。当扫描磁通量时，我们观察到避免了光谱中的水平交叉，提供了局部无序空间分布的详细指纹。通过结合这些方法，我们重建本征态的电子性质，观察持续电流和强抑制电导与添加的障碍。我们的工作描述了一种精确的量子模拟方法（5，6），并为研究具有超导量子比特的新量子材料铺平了道路。
A promising approach to study condensed-matter systems is to simulate them on an engineered quantum platform(1-4). However, the accuracy needed to outperform classical methods has not been achieved so far. Here, using 18 superconducting qubits, we provide an experimental blueprint for an accurate condensed-matter simulator and demonstrate how to investigate fundamental electronic properties. We benchmark the underlying method by reconstructing the single-particle band structure of a one-dimensional wire. We demonstrate nearly complete mitigation of decoherence and readout errors, and measure the energy eigenvalues of this wire with an error of approximately 0.01 rad, whereas typical energy scales are of the order of 1 rad. Insight into the fidelity of this algorithm is gained by highlighting the robust properties of a Fourier transform, including the ability to resolve eigenenergies with a statistical uncertainty of 10(-4) rad. We also synthesize magnetic flux and disordered local potentials, which are two key tenets of a condensed-matter system. When sweeping the magnetic flux we observe avoided level crossings in the spectrum, providing a detailed fingerprint of the spatial distribution of local disorder. By combining these methods we reconstruct electronic properties of the eigenstates, observing persistent currents and a strong suppression of conductance with added disorder. Our work describes an accurate method for quantum simulation(5,6) and paves the way to study new quantum materials with superconducting qubits.