Wang Xiqiao, Khatami Ehsan, Fei Fan, Wyrick Jonathan, Namboodiri Pradeep, Kashid Ranjit, Rigosi Albert F, Bryant Garnett, Silver Richard
Atom Based Device Group, National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA.
Joint Quantum Institute, University of Maryland, College Park, MD, 20740, USA.
Nat Commun. 2022 Nov 11;13(1):6824. doi: 10.1038/s41467-022-34220-w.
The Hubbard model is an essential tool for understanding many-body physics in condensed matter systems. Artificial lattices of dopants in silicon are a promising method for the analog quantum simulation of extended Fermi-Hubbard Hamiltonians in the strong interaction regime. However, complex atom-based device fabrication requirements have meant emulating a tunable two-dimensional Fermi-Hubbard Hamiltonian in silicon has not been achieved. Here, we fabricate 3 × 3 arrays of single/few-dopant quantum dots with finite disorder and demonstrate tuning of the electron ensemble using gates and probe the many-body states using quantum transport measurements. By controlling the lattice constants, we tune the hopping amplitude and long-range interactions and observe the finite-size analogue of a transition from metallic to Mott insulating behavior. We simulate thermally activated hopping and Hubbard band formation using increased temperatures. As atomically precise fabrication continues to improve, these results enable a new class of engineered artificial lattices to simulate interactive fermionic models.
哈伯德模型是理解凝聚态系统中多体物理的重要工具。硅中掺杂剂的人工晶格是在强相互作用 regime 中对扩展费米 - 哈伯德哈密顿量进行模拟量子模拟的一种有前途的方法。然而，基于复杂原子的器件制造要求意味着在硅中模拟可调谐二维费米 - 哈伯德哈密顿量尚未实现。在此，我们制造了具有有限无序的 3×3 单/少掺杂量子点阵列，并演示了使用门控对电子系综进行调谐，并使用量子输运测量探测多体状态。通过控制晶格常数，我们调整跳跃幅度和长程相互作用，并观察从金属行为到莫特绝缘行为转变的有限尺寸类似物。我们使用升高的温度模拟热激活跳跃和哈伯德带形成。随着原子精确制造不断改进，这些结果使一类新型的工程人工晶格能够模拟相互作用的费米子模型。
